In the House of Hyades: Sigma (σ), Theta (θ), and Delta (δ) Tauri

And now for something entirely different — binocular binaries.

Grab yourself a cup of something warm and have a seat beside me in a comfortable chair.  We’re going to tilt back into Taurus and enter the well lighted House of Hyades.  And in case you’re mystified by the reference to the Hyades, it’s the open cluster of stars between Aldebaran and the point where the “V” of Taurus come together just to the southwest of it.  But more on that later.

Now I have to tell you, binoculars and I have never hit it off.  My eyes just don’t want to be forced into looking through two large lenses at once.  And in addition to the fighting eyeball feedback, I frequently find I’m struggling to get a precise focus.  I don’t know about you, but I seem to prefer my photons finely focused — as in well done — and most binoculars I’ve used insist on serving up half-cooked views — as in medium rare.  Hope I’m not making you hungry.

But I do have a handy pair of 7×35’s that get used occasionally for quick glances.  For instance, if I’m trying to find an elusive star, or if I see a rare mysterious light in the sky — no contact with E.T. yet, though.   But somewhere deep in the recesses of my double star cluttered memory, I remembered Greg mentioning he was having great luck with his 15×70 Celestrons.  So when I saw a pair come up for sale, I decided to grab them to see how much better they would be than the small pair I ignore.  Tonight we’re going to use both pairs.

Because of their size, I have the 15×70’s on a parallelogram mount.   I tried using them without it and my arms began to feel like jelly within a couple of minutes.  So I’ll set them up beside your chair, and I’ll use the 7×35’s to guide us through this maze of stars.   And better throw this blanket over your legs — the dampness out here is a bit chilling tonight in this forty degree air.

One thing that will strike you immediately if you compare views in these is how much brighter the field is in the 15×70’s. I mean the stars really leap out at you.  I’ve caught myself ducking couple of times!

The Hyades Cluster, home of Sigma (σ), Theta (θ), and Delta (δ) Tauri. Click on this image, and those that follow, for a larger view. (Stellarium screen shot with labels added)

Now, this area not only features two multiple stars visible to the unaided eye — Delta and Theta — but it’s rich in visual pairs of stars that form some rather eye-catching patterns.

We’re going to start this tour with the beautiful reddish-orange Aldebaran, a first magnitude star located a relatively close 65 light years away from where we’re sitting tonight — just a hop, skip, and a jump out into the near reaches of our galaxy.  In the binoculars, though, I’ve noticed the color seems to be a bit pale — more like white with a reddish-orange tinge.  Take a look and let me know if you see the same thing.  Aldebaran has an 11.3 magnitude companion located a wide 133″ from it, which I think we should be able to pick out with at least the 15×70’s you’re using, except that the transparency is rather poor tonight.  So we’ll have to come back to it on a better night.

Splitting Tools: Obviously, since this is a post describing binocular friendly pairs, all of three of the pairs described below are ideally suited for binoculars, even small ones — hand held 7×35’s work well, but if you use anything larger, mounted would be better.  But they’re also great candidates for 50mm and 60mm scopes, provided you use low magnifications of about 20x or so.  Too much magnification will produce very wide pairs, giving the appearance of regular field stars.

Sigma-1 and Sigma-2  (σ-1, σ-2)  (Σ I 11)  (STFA 11)
HIP: 21683    SAO: 94054
RA: 04h 39.3m   Dec: +15° 55′
Magnitudes: 4.7, 5.1
Separation: 444.1″ (7.4′)
Position Angle: 194°  (WDS 2011)
Distances: 152 and 159 Light Years
Spectral Classifications: A4 and A5

OK — with Aldebaran in the center of your binoculars, if you let your eyes travel just a bit to the east you’ll come to the Sigma (σ) twins, σ-1 and σ-2.  They’re a visual pair, and they form a right angle triangle with sixth magnitude 89 Tauri just to their west.  Now  Sigma-2 (σ-2) looks white to me, and Sigma-1 (σ-1) is just a slightly different shade of white — it looks like maybe it has a slight tinge of yellow.  In Double Stars for Small Telescopes, Haas describes them both as brilliant yellow, but that was with a 125mm telescope which would provide a richer color than we can see in the binoculars.

What’s that?  So you see the yellow, too!  Great, I thought maybe my eyes were being tricked by the two little 35mm barrels on this pair I’m using.

Now you can take your choice of two eye-pleasing asterisms here — either the right angle triangle formed by the Sigma twins and 89 Tauri, or the parallelogram formed if you include the 6.6 magnitude HIP 21474 to the southwest of 89 Tauri.  Regardless of which you prefer, you’re guaranteed a stellar configuration either way.  I kind of lean toward that uniquely shaped parallelogram.

Oh, and to answer your question about the numbers attached to the Sigma pair: the -1 and -2 are assigned to them based on location.  The one farthest to the west gets the one, the next one to the east gets the two.  And if you look at the chart above, you’ll see that holds true for the Theta (Θ) twins and the Delta (δ) triplets.  Pay careful attention to this astronomical trivia — there might be a quiz when we get situated in the House of Hyades soon.

Theta-1 and Theta-2  (θ-1, θ-2)  (Σ I 10)  (SFTA 10)
HIP: 20894    SAO: 93957
RA: 04h 28.7m   Dec: +15° 52′
Magnitudes: 3.4, 3.9
Separation: 341.20″  (5.7′)
Position Angle: 348°  (WDS 2011)
Distances: 157.9 and 149.0 Light Years
Spectral Classifications: G7 and A7

I remember very clearly the first time I split these two stars.  It was without a scope on a night that was very clear and transparent.   I was looking up at Taurus because Aldebaran had caught my eye, and as I was enjoying the view of it and the Hyades, I suddenly realized I was seeing two very close, but distinct stars, just southwest of Aldebaran.  Now that really caught me off guard since I had never noticed them before, so I grabbed an atlas and identified them right away.  Since then, I’ve used these two stars frequently to gauge the transparency.  On a scale of one to five, five being the best, you need a four — above average — to pull off this trick.  And dark skies help a lot, too.

If you ask Jim Kaler, he’ll tell you the jury is still debating as to whether Theta-1 (θ-1) and Theta (θ-2) are gravitationally linked.  But Theta-2 (θ-2) has a companion located a mere couple of a hundredths of an arc second away — a little on the close side, and more than a bit beyond binocular range — which whirls around its parent once every 140.7 earth days.

We’re focusing now on the area within the circle! (Stellarium image with labels added)

Now if you position Aldebaran on the northeast side of your binocular field, Theta-1 and -2 will come into view over on the southwest side.  Both of these stars are white, but Theta-1 (θ-1) seems to have a slight tinge of red to me.  What?  You don’t see it?  Here, you better have some more hot tea.  You’ll be able to see the warmer colors better that way.  🙂

OK, if you start at  Theta-1 (θ-1) and let your eyes travel a bit to the northwest, you’ll come to fifth magnitude 75 Tauri, which looks to me to be white with a slight bit of yellow mixed in there somewhere.   Now, from Theta-2 (θ-2), look over to the east and you’ll find a pair of fifth magnitude stars, 80 and 81 Tauri,  with sixth magnitude 85 Tauri extending on a line beyond them to the northeast.  And just northeast of the Theta (θ) pair is another pair of stars, fifth magnitude HIP 21029 and 6.5 magnitude HIP 21053.

Now if you look into those binoculars closely — or at the chart above — that last pair, along with the Theta twins, and the 80/81 Tauri pair, form a very unusual triangle of three pairs of stars.  And, if you’re keeping track of all this for the quiz, you can add these notes: Both 80 and 81  are telescopic doubles — 80 Tauri has an 8.1 magnitude companion 1.6″ from the primary, and 81 Tauri has a 9.4 magnitude companion at a more distant 162″.

Like I said, this area is just full of eye-catching patterns.

But wait just a second.  Before you put those binoculars down to ask another question, look a bit closer at that triangle of double pairs and you’ll see …….

(Stellarium screen image with labels added, click to enlarge the House).

And you were wondering if we would ever get there.

Kind of leaves you breathless, though, doesn’t it.  Yeah, I know — star stuff does that sometimes. I wouldn’t take off that coat, though.  There’s no heat in that house, at least not from where we sit at about 150 light years away.

Actually, I have to thank Greg for pointing out this asterism.  It really is unique, and once your eyes recognize the pattern, it jumps right out at you.

And now that we have a home, the next thing we’re going to do is jump off the roof.  So let’s climb up to the peak, where 75 Tauri is located, and we’ll make a short leap straight up from it to the northwest and come down very gently right in the middle of the Delta (δ) threesome.

A leap to the northwest from the roof of the House of Hyades lands us right in the middle of the delectable Delta (δ) trio. (Stellarium screen image with labels added, click on the chart for a larger view)

And once more, another pattern emerges before our binocular fortified eyes.

Delta-1 (δ-1)                   Delta-2 (δ-2)               Delta-3 (δ-3)
Σ 1746                                      BUP 56                       H VI 101
HIP: 52913                                20542                           20648
SAO: 137808                            93907                           93923
RA:  4h 22.9m                     4h 24.1m                         4h 25.5
Dec:   +17° 49′                      +17° 27′                        +17° 56′
Mag:         3.75                              4.80                               4.30
Sep:                                 13.8′ from -1                43.2′ from -2
Dist: 153.2 LY                       145.9 LY                        147.9 LY
Spec:          K0                                  A7                                  A2

The Delta (δ) trio of stars forms a very recognizable triangle of just slightly more than ninety degrees.  As I look at them, Delta-2 and -3 appear to be the same shade of white, and Delta-1 seems to me to have a slight tinge of yellow to it.   You can see that, too?  Wow, our eyes must be on the same wavelength!

OK, now look closely at this area and you’ll see four pairs of stars to the southeast of Delta-2 (δ–2) that form an interesting pattern.  They caught my eye because the first two pairs (1 and 2 on the chart above) are arranged parallel to each other, as are the last two pairs (3 and 4) which point a bit more toward the south.  If you spend enough time here, your eye will no doubt detect other patterns.  I’ll leave that to you while I pour us some more tea.

Now the Delta (δ) trio are not gravitationally linked, which you can see if you look at their distances as shown above.  But each of them have companions, although those of Delta-1 and -2 are detectable only with spectroscopes or very large instruments.  The two companions of Delta-3, however, can be seen in a small to medium telescope.  The brightest is a 7.5 magnitude star at a tough distance of 1.5″, and the other is an 8.7 magnitude star located at a much more detectable distance of 77″.  I haven’t looked at these with a scope yet, but I’m filing a mental note right now to come back to them.

The Hyades

As we sat down at the beginning of this evening, I mentioned the Hyades cluster and described it as consisting of most of the stars between Aldebaran and the point where the “V” comes together at Gamma (γ) Tauri.  As you look at this area in the binoculars, or on the first chart above, it’s kind of difficult to form an image of a single cluster in your mind.  Instead, as we’ve just seen, what stands out is several groupings of stars.

So to make the “clusterness” of this cluster more visible, I listed the distances of all the labeled stars in the first chart.  I started with the Sigma (σ) pair and then worked my way to the southwest until I came to Gamma (γ) and then back up to the north.  Now Jim Kaler says the average distance of the Hyades cluster is fixed at about 152 light years, and that number begins to make a lot of sense if you look at the numbers on the chart below.

Just a quick glance at the distances you see on it shows that all but a few of these stars lie within a narrow range of 142 to 159 light years from us.  Out of the twenty-three stars in that list, only the four in red clearly stand out as non-members because their distances are nowhere close to that range.  The only one there is really any doubt about is HIP 21053.

And for a view of the Hyades in three dimensions — including a movie (!) — take a look at this site.

OK, what do you say we drop back in through the roof of the House of Hyades and see if the Hyadeans have any thing to eat.  Of course, I’ve never eaten there, so we might be better off to just get off this cold, damp deck, and go see what we can find in my kitchen.  At least it will look like something you’ve seen before.

And since you tolerated that maze of numbers on the chart rather well, we’ll just forget the quiz.  The images of all those star patterns in our memory will keep us mentally occupied for a while, anyway.

Cup of tea and a slice of cake?

(WDS data updated 9/9/2014)

A Sigh for a Psi (ψ) and a Sigma (Σ) Enigma: 23 Orionis; Psi (ψ) Orionis and Σ712; 33 Orionis and Σ721

When I was roaming and Rho-ing through Orion a week or two ago, I  banged my head rather hard on several double stars in the area north of where I was exploring.  After the swirl of stars around my eyes subsided (and my language improved 😉 ),  I made a mental note to come back and take a look at them.   Which led to the two evenings of observations described here — the first being a challenge to my balance, and the second resulting in some insight into eyepieces — what works, what doesn’t, and why  — that I had been mulling over for several months.   And of course, some out of this world double star observations.

But before you put your coat on to come out and join me, you might want to grab a couple of motion sickness pills.  The stars tonight look like the storm tossed lights of fishing boats on a wild and raging sea.

Fortunately, the first one on our list is separated by a reasonably wide 31.6 arc seconds of sky, so you won’t need to grip the railing too tightly.

The upper two-thirds of Orion is seen here, with our targets located halfway between Bellatrix and Mintaka. Click on this and any of the other images that follow for a larger view. (Stellarium screen shot with labels added).

23 Orionis  (Σ 696)  (H IV 84)            HIP: 25142    SAO: 112697
RA: 5h 22.8m   Dec: +03° 33′
Magnitudes: 5.0, 6.8
Separation:  31.5″
Position Angle: 30°  (WDS 2009)
Distance: 962 Light Years
Spectral Classification: B1

This one is easy enough to find — just draw a line from Mintaka, the westernmost of the three belt stars, to Bellatrix and point your telescope at the center of it.  In an 8×50 correct image finder with a four to five degree field of view, you’ll see an image that should match the chart shown below.  As you can see, all of the stars on our list are within a single field of view.  So for this session you won’t need to go to the  GOTO apparatus 🙂

All five of our stars are located within the circle, which represents the field of view in an 8×50 correct image finder. (Stellarium screen shot with labels added).

23 Orionis will be at the west edge of your field of view.  If you happen to be looking at Orion while it’s on or near the meridian, and are using a correct image finder, that would put it on the right side of the finder, just as you see it in the chart.

23 Orionis – note that the image is inverted to match the eyepiece view in my refractor. (STScI photo)

This is a nice, wide pair as I look at in my 60mm f/15 refractor equipped with a 20mm Plössl (45x).  The 6.8 magnitude companion is just close enough to suffer a bit from the glare of the fifth magnitude primary, so you may have to ogle it closely to see it, but once you pick it out, it’s easy enough to see — although with the horrible seeing tonight, it really takes some effort to hold the image of it steady.  I also have a four inch f/10 refractor out here tonight, and using the same 20mm TV Plössl (which gives me 50x), I can see the primary is a very respectable bluish-white, and the secondary seems to be almost identical in color.  Despite the squirrelly seeing, I put a 14mm Radian (71x) in the four inch scope to get a closer look at the secondary in order to confirm the color — and sure enough, it’s the same blue-white as the primary.  This double is one of those that Haas describes as a “showcase pair” in a 60mm refractor — and I’m sure it’s much better on on a better night than this one.  She sees “azure white and ashy blue” — which I think translates into bluish-white — but is a wording I wish I had thought of, and which really describes them well.

Because of the seeing — which by now is totally off the scale of rotten — I switch to a 24mm Tak (42x) in the four inch refractor, and the view improves considerably.  This really is a pleasing pair — if only they would hold still for half a second!!!

And, as I look now at the separation of the other stars on my list — 1.9″, 2.9″, and 3.0″ — I can see that it’s hopeless to try for them tonight, so I decide to give up and wait until tomorrow evening …………………….

Psi (ψ) Orionis (28 Orionis, or Psi-2)  (Knott 3 — KNT 3 in the WDS)
HIP: 25473    SAO: 112775 
RA: 5h 26.8m   Dec: +03°  06′
Magnitudes: 4.6, 8.6
Separation:  2.9″
Position Angle: 327°  (WDS 1991)
Distance: 1418 Light Years
Spectral Classification: B2

Σ 712  (H I 53)
HIP: 25443    SAO: 112765
RA: 5h 26.5m   Dec: +02° 56′
Magnitudes: 6.7, 8.6
Separation:  3.2″
Position Angle: 66°  (WDS 2007)
Distance: 509 Light Years
Spectral Classification: B9.5

…………………….. And here we are again!  Sure doesn’t take long to spend twenty-four hours around here!

And the seeing looks like it should be much better now because the stars don’t look like fireworks tonight — although I can’t really see much because of the murky haze.  But because Orion is one of the brightest constellations to grace our skies at night, I’m still able to trace its outline.  So what the heck, let’s get a scope set up and see what develops tonight and ignore the fickle forecast.  In consideration of the challenges we have ahead of us, I’m going to go with the AR-5, which is now equipped with a 60mm f/13.3 refractor that I attached to it last week while the rains were raining.

To test the seeing, I decide to take a quick look at Eta (η) Orionis, which has a separation of 1.7″.   I’m able to barely split it through the haze with a 10mm eyepiece (118x) in the AR-5, so it REALLY looks like we might just be able to get something done on these close stars tonight.

A quick look at 23 Orionis in the 60/800 at 40x is a bit better than last night because it isn’t jumping around, although in the haze the secondary is still tough to pick out.  But let’s move a bit to the east of it now and try our luck on Psi (ψ) Orionis and Σ 712.

Psi (ψ) is one of those stars that has more names than it does components.  Its Flamsteed designation provides it with the name 28 Orionis, Sissy Haas’s Double Stars for Small Telescopes refers to it as Psi-2, the Sky and Telescope Pocket Atlas designates it as just plain Psi, and the Cambridge Double Star Atlas calls it by two names, Psi and Knott 3  (G. Knott recorded some double star discoveries and observations in the 1860’s, but that’s about all the information I can find on him).   Overwhelmed by all those names, we’ll just sigh and call it plain old Psi — as in Ψ.

And if you’re curious, on our first chart Psi-1 is the star located to the south of Psi (ψ) which is labeled as 25 Orionis.

In the 60mm scope, both Psi (ψ) and Σ 712 are a wide pair that make a pleasant impression at 40x, even in the haze — which, by the way, is getting thinner (!) — and are even better in the 127mm aperture of the AR-5 at 49x.  What I’m looking for at the moment is Psi “B”, a dim companion at 327 degrees, just a bit west of north — and this is proving to be a tough one.  Eta (η) Orionis, at 1.7″ was easier, because there is only 1.3 magnitudes of difference between the two stars.  But here, even though the separation is greater at 2.9″, we’re dealing with a difference of four full magnitudes.  Which in plain language means the Psi (ψ) secondary is 40 times fainter than the primary, whereas in the case of Eta (η), the secondary is a little less than six times fainter than the primary.  To get that figure, you multiply 2.51 by itself for every full difference in magnitude between the components.  (For Psi, that’s 2.51 x 2.51 x 2.51 x 2.51 = 39.6)

At any rate, I’m not having any luck at all here.  I’ve worked my way up from an 18mm Tak LE (66x) to a 14mm Radian (84x), then a 12.5mm Tak (94x), and now I’m staring into a 10mm Tak LE (118x), and still cannot see the faint photons of that secondarial light.  Hmmm, I look down in the opposite corner of the eyepiece at Σ 712 —- and what in the name of Knott is this?

It’s a clean split.

Astounded, I back away from the scope now and look up at the sky for an answer from on high — and it’s cleared completely!  In fact, it’s absolutely stunning — black sky and gleaming stars everywhere I look.

But back to the scope.

What we have here is a failure to computicate.  By that I mean — first of all — that the 1.9 magnitude difference of the components of Σ 712 translates into “B” being about six times fainter than “A.”  Second — also in it’s favor is the greater separation of the two stars — 3.2″ here, versus 2.9″ for Psi (ψ) — a difference which really is more slight than significant.  And yes, as we’ve just seen, those two factors actually should make Σ 712 easier to split than Psi — BUT —  because the primary of Σ 712 is 2.1 magnitudes fainter than Psi (ψ) primary, I really had expected that it would be more difficult to split — as in less light, less luck.  So this Sigma is an enigma for sure — or maybe we’ve just learned something we can park in the memory banks for later use.

HOWEVER —  having succeeded so admirably with the photon friendly Σ 712, we now have a clue of what to look for as we heave a huge capital sigh (Ψ) of thanks and return to Psi (ψ).  Why?  Because the secondaries of both stars are the same magnitude — 8.6!  Aha!  A fortuituous unforseen stroke of photonic fortune!

So, glancing at the 8.6 magnitudes worth of photons glimmering from Σ 712’s secondary, I look very closely again at Psi (ψ) for a similar soft point of light  — and nothing.  Maybe the 10mm is causing too much glare, so I put the 12.5mm back in, and still there is nothing where that speck of light should be.  So I reverse directions and reach for a 7.5mm Tak (157x) and take another look — lots of glare, a slightly unsteady image, and no sign of Psi “B”.

OK.  There’s only one thing to do.  I go into the house and, from it’s hallowed location on a hall shelf, I remove the mysterious orange inscribed 7.5mm Celestron Plössl that has saved me from failure so many times in the past, and holding it with great care in the outstretched palms of my hands I return to the telescope and make the sacred switch.  As I slowly bring the image into focus, I notice there is virtually no scattering of light from the primary and that the image is more stable.  Already the magic is working, and I’m not quite focused yet!

A bit more, a bit more, just one more bit, and then another microscopic turn of the fine focus knob — THERE IT IS!

I got it, I got it, I got it,   I     GOT      IT!

Got what, you ask?  A very, very, very fine point of light — see it?  Not much more than a speck, really, but look!   It’s really there!

More magnification, you say?  Well, why not!

I put a 5mm Tak LE  (236x) into the diagonal, and again I get so much scatter from the primary that I can’t see past it to the secondary.  Well, it just happens that the mysterious 7.5mm Plössl has a mate that I haven’t been too impressed with yet, but I decide to give it a try.  Back in the house, open the box, and remove a 6.3mm Celestron Plössl (187x) of the same vintage and heritage as the 7.5mm.  Into the diagonal it goes, a few turns of the coarse focus knob, a few more turns of the fine focus knob — and slowly a sharp image begins to come into view — and LOOK! — it’s both stars again!

And it’s pretty darn steady, too.

I’m frozen into position —- shoulders hunched down, head bent forward over the eyepiece, right hand perched just beside the fine focus knob.  I have no desire to move from this spot for a couple of hundred years.  This is A-MAZING! One well-rounded, sharply defined yellowish white globe of light shadowed by a very miniscule, very fine, very faint point of light right at the top of it — that is as sharp and clear as it is faint.

Whew!  Get a grip, man!  You’ve been at this for an hour and half.  We still have another pair of stars to look at.

33 Orionis  (Σ 729)  (H I 22)         HIP: 25861    SAO: 112861   
RA: 5h 31.2m   Dec: +03° 18′
Magnitudes: 5.7, 6.7
Separation:  1.9″
Position Angle: 28°  (WDS 2011)
Distance: 1568 Light Years
Spectral Classification: B1.5

Σ 721  (H IV 45)        HIP: Not assigned in Simbad    SAO: 112824
RA: 5h 29.6m   Dec: +03° 09′
Magnitudes: 7.1, 9.1
Separation:  25.7″
Position Angle: 149°  (WDS 2010)
Distance: ?????
Spectral Classification: B5

Well, there’s no encore for something like that experience, so reluctantly we move on.

If you look at the second chart above, you can see that our next pair is on the east side of our finder field, and slightly north.  We’re not moving far, fortunately, so if these prove to be a disappointment, we’re going to go right back to the mesmerizing Psi (ψ).

You’ll notice if you position 33 Orionis in the northeast corner of your eyepiece, Σ 721 will be positioned on the opposite side of the field and a bit south.  Hmmm — this view is remarkably similar to that of Psi (ψ) and Σ 712.  Uh oh, here comes that deja vu feeling all over again  ……………..

But actually, with a 14mm Radian (84x) in the AR-5, 33 Orionis is a bit elongated, and I can see the split in Σ 721 with no problem.  I replace the Radian with a 12.5mm Tak (94x) and the elongation becomes a stretched out pair of stars that won’t quite come apart, so I remove the 12.5mm from the focuser and replace it with a 10mm Tak (118x), change the focus slightly, and —–

5 …… 4 ……… 3 ……….. 2 …………… 1 ………………………..    we have lift off!

Wow, that was a whole lot less struggle — and look at that view!  The primary is mainly white with a trace of blue, and hugging it closely — with a slice of black sky in between — the secondary is about half again as small and a little bit less white with a slight touch of yellow.  Both are very sharp and very vivid.

On the other side of the field, the primary of Σ 721 is pretty close to the color of 33 “B”, and I notice just the faintest tinge of red in the 9.1 magnitude secondary.  Now normally I wouldn’t expect to see any color at all at that magnitude, but I look several times, and with several different magnifications, and it’s still there.  You have to look closely at the sketch to see it, which approximates pretty well the way it appears in the eyepiece.

And just as I’m adding the last star to my sketch, I notice the field is getting dim.  I look up, and the entire western half of the sky is engulfed in fast moving clouds.  Usually, when there’s a sudden change like this, I can detect it in the eyepiece because the seeing begins to deteriorate quite quickly.  But not this time — it literally goes from clear to solid clouds in not much more than sixty seconds.  It really looks like someone has thrown a blanket over the entire sky, and it feels like it, too, as a damp west wind blows in at the same time.

So, don’t sit here and gawk — it’s liable to be raining in another few minutes!

A Word About Eyepieces

Eyepieces are like star colors — not everyone sees the same thing, and what you see on one night you may not see at all on another night.  Many are the things that affect the view through an eyepiece  — like aperture, focal length, baffling — not to mention seeing, transparency, moisture in the air, and what you had for dinner.

The Celestron 7.5mm has really done some marvelous things for me when I’ve had it in a focuser.   But, when I first got it, I was absolutely not impressed with it.  It went back in a box and stayed there for well over a year.  Similarly, the 6.3mm Plössl of that same line did not impress me at all when I got it about a month ago.  It wasn’t until I tried it on Psi (ψ) Orionis that I had any success with it.

The Tak LE’s are excellent eyepieces.  There is no question that their light transmission exceeds that of the two Celestron Plössls. But they do scatter a bit of light, and when there’s moisture in the air, or as in the case described above, I’m trying to split a close pair of stars separated by a wide range of magnitudes, they may not be the best choice.  Still, that’s not an absolute rule.  Tomorrow night they may work just great.

And the same applies to the Radians — superior light transmission and great contrast, but also a bit of scatter at times. And similarly, what works well tonight may not work at all tomorrow night.  Or, to put another spin on it, what fails tonight may succeed beyond your wildest dreams the following night.

So don’t interpret any of my comments on eyepieces as the definitive description of their peformance.  They aren’t.

What I try to do to deal with the issue is have a couple of different kinds of eyepieces of each focal length for the higher magnifications, since that’s where problems like those described above begin to show themselves.  In addition to the Taks and Radians, I try to blend in a few Plössls and Orthos because they have fewer elements of glass and because their fields of view are a bit more narrow.  For some reason — and I have no real idea why — the Plössls and Orthos aren’t affected quite as much by seeing.  Many times — and I’ve described it above and several times elsewhere — the image is more stable in the narrower fields.  But not always.  And if the seeing is really rotten, nothing makes any difference.

So take all of this as a reflection of my experience.  Yours could very well be different.

And if anyone quotes me, I’ll deny everything.  🙂

Rho-ing West in Orion: Rho (ρ), Eta (η), and Wnc 2

January 10th, 2011, 9 PM
OK – I’ve been clouded out for the past seven days, and according to the weather forecast, tonight’s clear skies are IT for at least the next week, so what to do to make the night interesting?  Well, heck, I’ll do what I always do in that situation — look at a few old favorites first!

Db Ds (Click on image for a larger view)

Tonight my 105mm f/14.3 refractor leads the way, and riding side-kick on top of it is a 60mm f/16.7 home built scope with a Carton lens.  I call this my Double Barrel Double Splitter combination – or Db Ds for short.  So after pointing the two scopes at Polaris and making sure the finder and the 60mm scope are aligned to the 105mm, I turn it back around to take a look at M42 and the Trapezium

Orion in all its beauty! Click on this and the other images for a larger view. (Stellarium screen shot with labels added)

Hmm …. bad vibrations.  As in bad seeing.  As in stellar jumping jacks in the eyepiece.  Not good, but pretty normal lately, so I just decide to back off of the magnification and live with it.  No sighting of “E” or “F” in the Trap, so up to Alnitak — the Flame Nebula is barely visible — and down to Sigma (σ) Orionis for a look at that quadruple system.  I’m able to pick out the faintest of that bunch of stars, the 8.8 magnitude “C” component, so now it’s back up north a bit to Meissa to see what’s going on there.  Not much, really — although Meissa and her three companions are stunning as always — but I can see the seeing is a bit better up here.   Still,  I have no luck with OΣ 111 to the north of it — I’ll split that thing one of these days!

By now I’ve been outside for about an hour and it’s time to take a short break from the 35 degree air and its 25 mph gusts of wind, so inside I go to get a cup of tea, warm up, and peruse my charts.  Since I’ve been poking around in Orion anyway, I look to see what’s “available” on the west side of it.  My eyes are drawn to Eta (η), which has a reputation for being difficult to split, and also to a star I looked at a couple of years ago with a very unusual name, Wnc 2, which I remember as dim and closely spaced.  Thinking about the poor seeing, I look over the area for something a bit easier.   Somehow I end up at Rho (ρ) Orionis — magnitudes of 4.6 and 8.5 with a separation of 7.1 arcseconds.   Hmmmmm ….. quite a difference in magnitudes for that separation.  But what the heck.  If you don’t try, you won’t fail.

So I put my coats(!) back on, pull my hat over my ears, pick up my cup of tea, and return to the cold land of the  whistling wind.

Rho (ρ) Orionis  (Σ 654)  (H N 21)         HIP: 24331    SAO: 112528
RA: 5h 13.3m   Dec: +02° 52′
Magnitudes: 4.6, 8.5
Separation:  6.9″
Position Angle: 63°   (WDS 2007)
Distance: 344 Light Years
Spectral Classification: K2

Enlarged view or our viewing area. Rho (ρ) is at the upper right, Wnc 2 towards the center and next to 27 Orionis, and Eta (η) is below it. (Stellarium screen image with labels added)

My charts tell me that if I start at Mintaka, the westernmost of the three belt stars of Orion, and follow the line formed by those three stars for a distance of 1.5 times its length, I’ll come out just barely north of Rho (ρ) —  and it works like a charm.  So I sight down the length of the 105mm tube, look in the finder, center it, and then — not expecting a lot of luck — peek into the 83x of an 18mm Radian.

And there they are!  Both stars!  Just like that!  No searching, no squinting!  No failure here!  The 8.5 magnitude secondary is a very fine point of light next to an orange primary, and both are just as obvious to my eyes as the sinking crescent moon in the west.  And to top it off, I can see that little pinpoint of fine light in the 20mm eyepiece (50x) of the 60mm scope.  Now that I find hard to believe!

I swap a 15mm Plössl (67x) into the focuser just to confirm it isn’t my imagination.  It isn’t.  I try an 11mm Plössl (91x) next, but it’s actually a bit too much because it’s magnifying the glare from the orange primary.    Now I move the 11mm Plössl to the 105mm scope, which gives me 136x and very little interference from the glare.  But the best view is really at 100x with the 15mm Plössl.  And faint as that secondary is, I can definitely see a blue tint to it!

Not bad for the first part of an unplanned observing plan!

Eta (η) Orionis  (Saiph al Jabbar)  (Dawes 5 — DA 5 in the WDS)  (H VI 67 — AC only)
HIP: 25281    SAO: 132071
RA: 5h 24.5m   Dec: -02° 24′
Magnitudes  AB: 3.6, 4.8       AC: 3.6, 9.4
Separation   AB: 1.8″             AC: 115.1″
Position Angle  AB: 77°  ( WDS 2011)        AC: 51°  (WDS 1998)
Distance: 901 Light Years
Spectral Classification: B1,B2

Well ……. since I’m off to a good start, why stop?  On to part two of this stellar version of Mission Impossible.

Eta (η) is easy to find — just draw a line from Mintaka to Rigel, and you’ll see it about a quarter of the way from Mintaka, a bluish white star like most of the bright stars in this area.  It occurs to me that from the perspective of prudence, it would be smart to stay with the 105mm scope on this one — 1.8 arcseconds in this kind of seeing is going to be a stretch.

I start with a 14mm Radian (107x) and can see the image is elongated just a bit horizontally.  So I move up a short step with a 12mm Radian (125x) and that elongated form is desperately trying to pull itself apart.  A 10mm Plössl (150x) really isn’t much better, but the way the image is weaving and wobbling, I’m wondering if there’s any point in going further with this.

But what the heck — someone, I believe it was me — said, “If you don’t try, you won’t fail!”  So, here goes.

I walk into the house to find some warm air and my next two tools of the trade — a 9mm UO Ortho (167x) and a magical 7.5mm Celestron Plössl (200x).  If Mission Impossible it is, then we’ll dig deep before pushing the self-destruct button.

Back out in the cold, I remove the 10mm Plössl and carefully place the 9mm Ortho in the diagonal.  I bend slowly down to the eyepiece with both eyes closed, carefully open my right eye — and —- and —– and ——  BINGO!   Two touching globes of light!  At least for brief moments when the seeing settles down.

So this calls for the mysterious magical powers of that very unique 7.5mm Celestron Plössl that I found in a box of parts given to me by a neighbor a couple of years ago.  With a sense of regret and hating to break the bond that has just formed between me and the 9mm Ortho, I reverently remove it and gingerly replace it with the 7.5mm.

Magical, mysterious, maybe even miraculous!

Can you stand this suspense?  NO?  Well hang on, anyway, because here we go  —— with a feeling of stirring anticipation and a sense of impending I awe, I place that little 7.5mm eyepiece in the diagonal —– and  —–   GOT ‘EM!   The magic eyepiece has done it once more!

What I see are two very distinct, very separate globes of light, which surprisingly, have a slight yellow tint to them.  And Haas noticed that also: “straw yellow and silvery yellow” is her description.  What these two stars really remind me of is Porrima.  When I split it last summer, it was near the meridian, so the two components were stacked one above the other in my eyepiece.  Eta (η) is also near the meridian tonight, and it’s pair of stars is lined up horizontally in the eyepiece — but other than that, they look remarkably similar.

Well, it just does not get any better than this. 🙂

Wnc 2        HIP: 25240    SAO: 132060
RA: 5h 23.9m   Dec: -00° 52′
Magnitudes: 6.9, 7.0
Separation:  3.1″
Position Angle: 159°  (WDS 2011)
Distance: 189 Light Years
Spectral Classification: F6

Alright, back down to earth now for a few moments to plan a strategy for locating our last pair.

Looking at the chart above, you can see that Wnc 2 forms a triangle with Mintaka and 31 Orionis, as well as with Eta (η) and 31 Orionis.  But I’m standing outside at the scope in a cold wind using the Sky and Telescope Pocket Atlas to star hop, not inside looking at a computer screen.  I’m holding the atlas in my left hand, with a small red flashlight clamped between it and my left thumb, guiding the 105mm refractor with my right hand, while looking into the eyepiece of a correct image 8×50 finder.  And I’m having no luck at all.

And the reason is that the image in the atlas — which also is the case in the Cambridge Double Star Atlas — shows a larger and brighter star at the location of Wnc 2 than what is actually there.  In other words, the image in the finder is not matching the atlas well at all.  After a couple of futile attempts, the lights come on in my chilled brain and I decide the smart thing to do would be to center 27 Orionis — which I can clearly see — in the finder, and then look in the eyepiece of the telescope.  So I do — and darned if I don’t see the little devil off towards the west edge of the eyepiece.

Geeez — I oughta do this for a living.

West is to the upper left in this refractor (mirror image) view.

Now this one is not really all that stunning, but the satisfaction of finding it more than makes up for that.  In the 105mm refractor, using a 14mm Radian (107x), this is a close pair, as well as relatively dim, which the sketch here shows pretty well. With a 15mm Plössl (67x) in the 60mm refractor, though, the stars are just barely separated.  Haas apparently didn’t look at them, but quotes an observation by Castle which describes the stars as ” ‘warmish’ without an obvious color.”  Yep, too dim for color, but by this time I would have welcomed a “warm” tone if I had seen it.

Now what in the name of the Orion Nebula does Wnc 2 stand for?  A quick look in the Cambridge Double Star Atlas reveals at least a name — F. A. Winnecke.  The full name is Friedrich August Theodor Winnecke.   Herr Winnecke was a German astronomer who published a list of seven double star “discoveries” on February 8th, 1869, some of which it turned out were already known.  More info on him can be found here,  and his list of seven stars is here.   If you look at that list, you’ll see that the double listed as Wnc 2 is in Eridanus, while the info for Wnc 3 matches the Orion coordinates.  Both the Haas book and The Night Sky Observer’s Guide, as well as the Washington Double Star Catalog, list the one we’re looking at as Wnc 2, however, so it appears that the list on the link has reversed the two.

And ….. that’s it for tonight.  Sorry, but it’s cold out here, the clouds are coming in, and I hear another cup of hot tea calling to me.

And since the weather forecast is calling for another week of rain starting in the next few hours, I need to go back to building my ark and practicing my Rho-ing technique.

Clear Skies!

Under the Left Horn of the Bull: Σ730 and h 3275; Σ674 and Σ680; Σ740 and Σ742

Taurus is seen here hovering over Orion. Click once on the image (and any of the others that follow) to enlarge it. Note that the “left” horn of the bull is in reality the horn on the east side of Taurus. (Stellarium screen image with labels added)

It’s surprising sometimes how close constellations are to one another.  For instance, I don’t habitually think of Orion and Taurus as bordering each other, although I know full well they do.  They just seem like they should be farther apart.  In reality, the top of Orion’s shield (which really looks much more like a bow to me) almost reaches to Aldebaran, and the distance from Meissa (Lambda Orionis) to the Crab Nebula (M1) is barely over ten degrees.  So I was surprised — once more — when I discovered the first of our pair of doubles is only six degrees north of Meissa.

So strap yourself in to your observing chair because we’re going for a ride on the Bull — but since all three of the pairs we’re going to look at lie within a relatively small area of sky measuring four degrees by four degrees, we’ll keep it short!

h 3275               HIP: 25745    SAO: 94589
RA: 5h 29.8m   Dec: 18° 25′
Magnitudes: 7.7, 8.2
Separation: 56.3″
Position Angle: 21°  (WDS 2002)
Distance: 653.6 Light Years
Spectral Classification: A0

Σ 730  (H N 124)          HIP: 25950    SAO: 94630
RA: 5h 32.2m   Dec: +17° 03′
Magnitudes: 6.0, 6.4
Separation:  9.4″
Position Angle: 142°  (WDS 2007)
Distance: 1117 Light Years
Spectral Classification: B7

Using the chart above, we’ll start our trip at Meissa.  You’ll find it located at the top of Orion just north of a line drawn between bright reddish-orange Betelgeuse and blue-white Bellatrix.   Move north eight degrees from Meissa and — if you have relatively dark skies — you should see the faint reddish-orange glow of 119 Tauri without optical aid — or you can use a pair of binoculars, in which case you won’t be able to miss it.  But if that doesn’t work well for you, draw a line from Meissa to Zeta (ζ) Tauri, then backtrack about two degrees and you should see 119 Tauri just to the west of that line.  In a finder with a four to five degree field of view,  you should easily be able to see Zeta (ζ) and 119 in the same field.

Σ 730 and h 3275, and the surrounding area. (Stellarium screen image with labels added)

119 Tauri is a very interesting star all by itself, a class M2 giant much like Betelgeuse, located about 1900 light years from us.  Once you have the beautiful gleam of this reddish-orange star centered in your eyepiece, you’ll see h 3275 about half a degree to the southwest.  It’s a widely spaced pair of stars that is very obvious in a small scope.  I was using a pair of scopes side by side — an old 80mm Mizar equipped with an f/15 Carton lens and a Tasco 60mm f/16.7.  A 25mm Plössl (48x) in the first scope and a 20mm Plössl (50x) in the second one provided similar views.  Both components are basically white in color, although at magnitudes of 7.7 and 8.2, the color is not particularly striking.  The “h,” by the way, is a reference to John Herschel, who is credited with the discovery of this one.

A move of 1.5 degrees south will bring you to Σ 730.  Considerably brighter, and much more closely spaced, it provides a wonderful contrast to h 3275.  With a 30mm Tak LE (33x) in the 60mm scope, I could just barely fit h 3275 and Σ 730 in the same field of view.  In the eyepieces I mentioned above, though, I found Σ 730 really stands out well when centered because it’s the brightest pair of stars in the field.  This one deserves Haas‘s description as a “showcase pair” in a 60mm scope, and I think her “blue-white and yellow-white” pretty well covers it also.

Of the two pairs, Σ 730 is certainly the most appealing.  But in addition to the contrasts in brightness and spacing, what really caught my attention was the contrast in position angles.  Σ 730 lines up in a south-easterly direction, and h 3275 aligns to the northeast, which adds to their appeal when seen in the same field.  Also particularly eye-catching is the arc to their west which is formed by 117, 113, 110, 111, and 115 Tauri.  These look best in the finder, or even better, a pair of binoculars.  No name has been given to this arcing asterism, so I’ll call it the Bull Cluster, or BC for short!

Σ 674          HIP: 24663    SAO: 77084
RA: 5h 17.5m   Dec: +20° 08′
Magnitudes: 6.8, 9.7
Separation: 9.9″
Position Angle: 149°  (WDS 2009)
Distance: 239 Light Years
Spectral Classification: F7, F5

Σ 680           HIP: 24820    SAO: 77098
RA: 5h 19.2m   Dec: +20° 08′
Magnitudes: 6.2, 9.7
Separation:  9.5″
Position Angle: 206°  (WDS 2011)
Distance: 431.4 Light Years
Spectral Classification:  K0

Σ 680 is the brightest of these two pairs, so “theoretically” it should be the easiest to find.  There are two ways to get to it.  First, if you’re starting from the  h 3275/119 Tauri area, move three degrees to the northwest.  Or, if that proves difficult, start from Zeta (ζ) Tauri, the star that marks the top of the bull’s left horn and move northwest past 114 Tauri to 109 Tauri, a total of four degrees — both of these last two stars can be picked out of a dark sky without optical aid.  From 109 Tauri, move south two degrees, and you’ll come to the distinctive parallelogram formed by Σ 680 and Σ 674 and the two stars to their south.

Σ 680 and Σ 674 are seen here in the middle of this image, and our next pair of stars, Σ 740 and Σ 742, are at the upper left. (Stellarium screen image with labels added)

As my subtle hint above should indicate, though, these two are a bit elusive.  The first night I searched for them, I was using the 60mm and 80mm scopes described above in the  h 3275/Σ 730 discussion.  I had a heck of time locating these two stars because I couldn’t detect the faint components of either one.  I searched, and searched, and searched  ……………  and kept ending up at the same place — but without any sign of a split.  I tried several times from both the 119 Tauri area and the 109 Tauri area.  In fact as I discovered later, I could even pick out Σ 680 visually with averted vision.  But without a split to confirm I was looking at the correct stars, I just couldn’t be sure I was where I wanted to be.  As my old Uncle Harry used to say, “Son, if it ain’t workin’, don’t keep doin’ it harder.”

And it wasn’t.  So I didn’t.

I went on to other things muttering about stellar stuff quietly enough not to disturb the neighbors.

Reproduction of sketch of Σ 680 and Σ 674 – the black arrow at the upper left points to west in this image to match the eyepiece view.

HOWEVER —– I don’t give up easily.  The next night I was back — and this time with a larger Star-Splitter, the Meade AR-5.  I don’t remember what I paid for this gem, but for a light grab-it-and-throw-it-on-the-mount scope, it’s been a heck of a bargain.  So, to get to the point, I was looking in the right place the previous night, but I just didn’t have enough aperture.  When I pointed the AR-5 at Σ 680, there was the faint companion, clear as could be, and over on the left side of the field about thirty arc minutes away, Σ 674 was even more obvious.  And what a delight! — two primaries of almost the same brightness accompanied by two pinpoints of light that were about equally faint.

As for colors, the 6.2 magnitude primary of Σ 680 had a slight, but obvious, orange tint in the AR-5 at 74x;  the 6.8 magnitude primary of Σ 674 was white with a tinge of blue to it.  Of the two pairs, the secondary in Σ 680 was more difficult to see because of the larger difference in magnitudes and also because it’s almost eight tenths of an arc second closer.  And working at these faint magnitudes, that’s just enough to be significant.

I also had my 63mm Zeiss out that night, so now that I knew I had the field correctly identified, I pointed it in the correct direction, lined up what by now was a very familiar field in the finder —- und Heilige Sternen im Himmel! —- was able to split both stars with a 15mm TV Plössl (56x)!   The Σ 680 secondary gave me a bit of trouble, but I did manage to hold it with direct vision for several seconds at a time.  I really don’t think I would have ever seen those two faint specks of light without first having seen them in the AR-5.  Knowing EXACTLY where to look, and just as important, HOW to look, makes a huge difference in a person’s ability to see faint objects such as these.  And Herr Zeiss deserves a bit of credit, too – Vielen Dank, mein Herr!

Σ 742  (H I 70)               HIP: 26328    SAO: 77313
RA: 5h 36.4m   Dec: +21° 59′
Magnitudes: 7.1, 7.5
Separation:  4.1″
Postion Angle: 275°  (WDS 2012)
Distance: 212.5 Light Years
Spectral Classification: F8
Status:  Physical, orbital chart and data can be seen here.

Σ 740                             HIP: Not assigned in Simbad    SAO: 77308
RA: 5h 36.4m   Dec: +21° 11′
Magnitudes: 9.0, 9.9
Separation:  21.7″
Postion Angle: 121°  (WDS 2004)
Distance:  ?????
Spectral Classification: B2

A quick glance at the upper left hand corner of the above chart for Σ 674 and Σ 680 will show you the location of our next two stars, Σ 740 and Σ 742.  Both of these lie very close to bluish-white Zeta (ζ) Tauri, a B class giant of a star located 420 light years from us.  A look at the more detailed chart below (a mirror image view which matches that seen in a refractor equipped with a diagonal) shows Σ 740 lying immediately west of Zeta (ζ) Tauri.  In fact, anyone who has spent much time looking at the Crab Nebula (M1) will find that both of these double stars are a familiar sight.  Haas’s description is very accurate: “A close pair of bright stars, and a wide pair of dim stars.”

Mirror image (west and east reversed) to match the view as seen in a refractor using a diagonal. (Stellarium screen image with labels added)

Σ 740 is certainly not an attention grabber, and determining color is out of the question because of the faint magnitudes of the components.  Faint — but well within the reach of a 60mm refractor because of their relatively wide separation.  I could split it easily in the Tasco 60mm f/16.7 with a 25mm Plössl (40x).

If you’re using an eyepiece with a field of view of about 1.3 degrees, you can see Σ 742 at the north edge of your eyepiece if you position Σ 740 at the opposite, southern, edge.  In fact if you look closely at the coordinates above, you’ll find both of these pairs of stars have the same right ascension, so all you really need to do is just slide up that imaginary line in the sky to get there!

On the other hand, if the field of view of your eyepiece is too narrow to see both pairs at the same time, center the line of four stars which lie on the opposite side of Σ 740 from Zeta (ζ) Tauri, draw a line northeast from the southernmost of the four (it’s labeled with a magnitude of 8.2) to the northernmost one (labeled 7.6), and continuing in that direction, nudge your telescope just a bit until Σ 742 comes into view, probably with the Crab Nebula at the west edge of your eyepiece.

With a separation of 4.1″, this is the closest of any of the doubles we’ve looked at here.  In the 60mm f/16.7, it was clearly elongated with a 30mm Tak LE (33x) — almost split, but not quite.  I had to move up to a 20mm Plössl (50x) to get a clean split, but when I did, it was a beauty to look at — two barely separated points of light of almost identical brightness.  While each of the components were white in the 60mm and the 80mm scopes, I thought a detected a slight tinge of very faint red in the primary on the next night when I looked at it with the Meade AR-5 at 59x.  The best view I had in all three scopes was in the AR-5 with a 16mm Meade SWA (74x) —– ravishing, riveting, rousing even!

And through it all, the Crab Nebula hovered at the west edge of the field like a ghostly presence.  Here’s a sketch from Jeremy Perez’s web site, which is far more likely to resemble what you see in the eyepiece of your telescope than a photograph will.  But we can’t pass pass up a chance to see a good photo of the Crab either, so here’s an image of it captured by the Hubble Space Telescope.

These observations were made on the dark frigid nights of Jan 2nd and Jan 3rd, 2011.  Information about 119 Tauri can be found here, and for Zeta Tauri, look here, both of which are pages from James Kaler’s web site.

And the German means “Holy Stars in the Sky!”  — but it has a certain tone in German that it loses in translation.

And speaking of the sky, I hope yours are clearer than mine!  😎

The Proud Head of Orion: Marching with Meissa (Lambda [λ] Orionis) and OΣ 111

Majestic Orion! Click on this and any of the following images for a larger view, and then click a second time to enlarge the view once more. (Stellarium screen image with labels added)

Situated halfway between bright orange Betelgeuse and blue-white Bellatrix  and about three degrees to the north, Meissa is a busy little devil.  It anchors a large open cluster, Collinder 69, and illuminates a large ring of gas 150 light years in diameter.  Meissa “A” is a very hot star sporting a sizzling temperature measured at 35,000 Kelvin, and Meissa “B” is just barely cooler at 27,000 Kelvin.  At those temperatures, they each send a tremendous amount of energy into that cloud of gas. “A” radiates 65,000 times more than the sun and “B” drops down to a comparatively smaller, but still considerable,  5500 times more than our own star.  The source of the name is somewhat vague, but James Kaler’s best guess is it’s from the Arabic for “the Proudly Marching One.”

A closer look at the Betelgeuse-Bellatrix-Meissa area. (Stellarium screen image with labels added)

In a telescope, Meissa and the surrounding area is a beautiful sight at any time, but especially for my photon deprived eyes after a lengthy run of rotten viewing weather.  South of Meissa are two fourth magnitude stars, Phi-1 (Φ-1) and Phi-2 (Φ-2).  This pair combines with Meissa to form a slightly tilted irregular triangle.    Phi-1 is a class B0 star located at a distance of 985 light years, and Phi-2, which to my eyes has a very distinctive reddish-orange flavor to it, is a G8 star at a much closer 116 light years. Inside that triangle is a line of three north-south aligned stars.  The northernmost has a magnitude of 7.6,  and the next one to the south is at 7.5.   The southernmost one, HIP 26212, is a class B2 star with a magnitude of 6.7 sitting way out there at the sizable distance of 1388 light years.  Burnham comments that the moon would actually fit within this triangle, which measures twenty-seven arc minutes on the west side and thirty-three along the south edge.  Completing the telescopic scene is OΣ 111 (STT 111), sitting about 14 arcminutes north of Meissa.  This one is another double, with magnitudes of 5.6 and 9.7 separated by 2.9″, positioned at a distance of 1463 light years from us.

So as should be rather obvious from this long introduction,  pleasing photonic opportunities abound in this very small area.  And as I alluded to earlier, my opportunities have been severely curtailed for the past five weeks due to a parade of very wet clouds that were considerate enough to drop thirty-three inches of rain on my observing sight as they passed through.  I tried several times to get a peek at Meissa through sucker holes, but as usual, the clouds waited until I was lined up and then leaped back across my view.  I even managed to get rained on twice during those futile frustrating attempts.  So pull up a chair and make yourself comfortable, because we’re going to spend some time here — no looking and leaving, no viewing and vamoosing — we’re going to sit and stay!  My goal is to become so familiar with this wonderful area of sky that I can call up an image of it in my memory quicker than you can swap browser screens.

Finding this area is easy – as described above, from a point midway between Betelgeuse and Bellatrix, move north a few degrees.  If you have reasonably dark skies, you’ll see a faint triangle of three stars just north of that line, which represents the head of Orion.  Moving from east to west and then north, these stars are Phi-1, Phi-2, and Meissa.  In a finder with a four or five degree field of view, this entire area — from the Phi twins up to OΣ 111 — is a an eye-catching open cluster known as Collinder 69, and it’s especially attractive due to the three north-south aligned stars between Phi-1 and Meissa.   I dropped a 26mm Plossl (30x) into the focuser of my AT-111, which gave me a reasonably wide 1.7 degree field of view —— and I could feel all the rusty corroded connections in the dim recesses of my astronomical memory coming to life once again as the photons flew through them!  What a sight for star starved eyes!  The Stellarium screen image below gives you a hint of what it’s like, but don’t take my word for it — go out and take a look!

Image as seen in the eyepiece of the AT111 at 56x – note that east and west are reversed. (Stellarium screen image with labels added)

So, on to the serious stuff — Star Splitting!!!

Meissa  (Lambda [λ] Orionis)   (Σ 738)  (AB is H II 9)       HIP: 26207    SAO: 112921
RA: 5h 35.1m  Dec: +09° 56′
Magnitudes    A: 3.5     B: 5.5     C: 10.7     D: 9.6    E: 9.2
Separation     AB: 4.2″      AC: 28.7″      AD: 78.0″    AE: 150.4″
PA    AB: 44° (WDS 2011)   AC: 185°   AD: 272°   AE: 279°  (C, D, & E all WDS 2008)
Distance:  1056 Light Years
Spectral Classification    A: O8    B: BO.5

Now Meissa “B” is not particularly difficult to see, so I started with a 14mm Radian (56x) in the AT 111 and was just able to glimpse it clinging to the side of the primary, and about an arc minute off to the west, “D” was also easy to pick out of the glare, and “E” is easy to see hovering all by itself out beyond “D”.  Out with the 14mm and in with a 12mm version (65x) and “B” became a perfectly round white dot of light just out of hugging range of “A,” and “C” now came into view with averted vision.  I’m not in a hurry here ;), so the next move was to a 10mm Radian (78x) which gave me a slightly larger, but essentially similar view.  Still savoring the moment, I reached for the 8mm Radian (97x) — which allowed me to pick out “C” with direct vision, although it was difficult to hold for long.  One more magnified leap forward, to a 6mm Radian (130x), and I was able to hold “C” with direct vision for long periods of time.   Searching for an aesthetic alternative, I dropped back to a 7.5mm Tak LE (104x) and was surprised at how steady “C” was in it.  And then, backing away from my focus on the four Meissa components, I went back to the 14mm Radian and took in the entire field of view once more.  As I sat there for several minutes absorbing the beauty of it, I noticed “C” was occasionally visible out of the corner of my eye.

The primary I saw as white and “B” I would call gray, but Haas saw “lemony white and ashy blue-violet,” which are the colors hinted at in the sketch.  (East & west reversed to match the refractor view, click to lose this caption).

Two nights later I returned with a Tasco 60mm f/16.7 for another look, mainly curious about the different perspective provided by the smaller aperture and the longer focal length.  With a 26mm Plössl (39x) I needed averted vision to pick out “D,” but was able to see it with direct vision when I moved up to a 20mm Plössl (50x) — and “E” was obvious, thanks to it’s greater distance from all the glowing that was going on closer in.  With 15mm (67x) and 11mm Plössls (91x) I was able to glimpse “C,” but it was difficult because of the cloud of gas which is illuminated by Meissa “A.”

There was something noticeably different about this view, though.  Of course, it wasn’t as bright and the stars were slightly dimmer in comparison to the four inch aperture of the scope I used two nights earlier, but those weren’t surprises.  Instead, it was the compactness of the view that intrigued me.  The field of view in the AT111 using the 14mm Radian comes in at 1.06 degrees, while the 20mm Plössl in the Tasco gave me .98 degrees — so, from a numbers standpoint, they’re essentially the same.  But the entire field in the Tasco was just “neater,” as in “freshly pressed” (with a stellar iron)  — which I’m pretty sure was just a result of the smaller image scale resulting from the smaller aperture.  That’s not to say the view in the AT111 was lacking in any way — just that it was not the same.  Everyone has their preferences, and those will change over time.  On that night, I preferred the view in the 60mm.  Next week — if it’s clear (!) — I may lean back to the AT111.

Now about that gas cloud that Meissa illuminates with so much energy: I can’t honestly say I’ve ever noticed it prior to these two nights, but it really was not difficult to see in either the 111mm or the 60mm refractor.  If you look right at Meissa “A,” you won’t see it — but if you avert your vision just a bit, it pops right into view.  I could see it quite easily at both low and high magnifications that way.  Most of the time it had an oval shape, extending about an arc minute to the east of “A” and as far west as “D.”  And I noticed in an 8×50 finder it appears slightly larger than that.

OΣ 111 (STT 111)         HIP: 26215    SAO: 94671
RA: 5h 35.2m  Dec: +10° 14′
Magnitudes: 5.6, 9.7
Separation:  2.8″
Position Angle:  351°  (WDS 2003)
Spectral Classification: B9
Distance: 1463 Light Years

Up to this point, I’ve neglected poor old OΣ 111, which sits on the north fringe of this cluster of stars.  Looking at the statistics, I could see this was going to be a difficult one to split, but based on experience, it certainly didn’t strike me as being out of range.  Both nights I was out, the seeing was below average — well below on the first night with the AT111, just on the negative side of average on the second night when I tried with an AR-5.  On that first night of no luck, I stopped with a 5mm Tak LE (155x) because the image was bouncing around so badly I couldn’t hold it in view for more than a fraction of a second.  I was sure I could nail it, though, the next time out with the five inch AR-5.  Again, no luck, and again, I had to give up because the image was bouncing around so badly I would have needed half a dozen motion sickness pills to keep at it.  I may have had a glimpse of it with the 5mm Tak (236x), but it was so fleeting it was impossible to be sure.  I gave a 4mm Plössl (295x) a try, but it bounced out of the field of view more than it was in it.

I’ll come back to this one on a night when the seeing is better.  I suspect what I’ll find is the companion is a very small pinpoint of light.   If you, the reader, happen to split this elusive little devil, by all means post a comment here and let us know.  We would be honored to have it on this site.

These observations were made on the evenings of two different years:  December 30th, 2010, and Jan 1st, 2011.  🙂   Data on Meissa is from Jim Kaler’s web site, which is highly recommended!

Alnitak (Zeta Orionis) – A Flaming Delight – and its Neighbors, Sigma Orionis and Σ761

Alnitak, with the “B” and “C” components lost in the glare. Click on the photo for a larger version. (STScI photo)

There is something about that name – Alnitak, from the Arabic Al Nitak – that evokes an image of restrained elegance.  In my eyes that elegance is seen in the bluish-white glow it radiates into the eyepiece of a telescope.  In Arabic, it means “the girdle,” which I believe is a reference to the belt of Orion, not the confining modern day garment that leaps to mind.  Despite being 817 light years away, it’s very close to being a first magnitude star, which is no surprise given that it’s luminosity in the visible spectrum is 10,000 times greater than our sun.  As the attached photo shows, it’s more than capable of lighting up the clouds of interstellar gas in the area surrounding it.  And, as James Kaler discusses here, it has the distinction of being the brightest class O star in the sky.

Plagued by the expected rainy November which is normal for the north Oregon coast, I was thrilled to have a clear night about a week ago — even though the moon was full.  In this part of the world you take what the weather gods offer.  However —  the full moon of winter is not the full moon of summer.  In those warmer months it sits much lower in the sky, radiating a soft yellow light that actually can make an evening of double-star observations very pleasant if you keep it at your back.  But the winter moon is like turning on a 1000 watt flood light in a small closet lined with aluminum foil.  Because it makes a higher arc through the heavens, the entire sky is flooded with its brilliant white light.  Add in the atmospheric scatter caused by the dampness which is typical of this time of the year, and it becomes downright obnoxious.

So there I was, under a clear bright sky, wondering what to look at.  My plan was to stay as far away from the moon as possible, so I toured some of the doubles in Cassiopeia, Cepheus, and Draco that Greg and I have written up over the past few months.  But even though I was 180 degrees away from the moon, they were darn hard to pick out of the bright sky.  Kappa (κ) Cephei kept doing a disappearing dance while I tried to sight it through the Telrad, and I managed to stumble across Epsilon (ε) Draconis by pure luck.  But the seeing was reasonably steady, and the moderate magnification I was using provided some rewarding sights.

After a couple of hours of that, I had developed a stellar appetite for something more thrilling, something with a bit of a challenge, something bright and faint at the same time, something with a bit of gleaming interstellar gas even.  And then I saw it — rising over the roof of my house  —-  Orion.

Betelgeuse —  Rigel — those three gleaming belt stars — the cloud of glowing gas just below them.  Irresistible.

Stellarium screen shot with a few labels added. Click once for a larger view and then a second time for a still larger view.

I don’t care how many times I look at the huge, sprawling outline of this constellation, I can never get enough of it, full moon or not.  There just isn’t anything in the sky that grabs my attention like that configuration of gleaming stars.  If Orion didn’t exist, it would have to be invented.

So of course I took a look at the Trapezium — thought I could just get a hint of “E” —  worked up through the open cluster north of it — NGC 1981 — and bumped into Alnitak as I continued north to the three belt stars.

Alnitak  (Zeta [ζ] Orionis)  (Σ 774)  (AC is H IV 21)        HIP: 26727    SAO: 132444
RA:  05h 40.7m   Dec:  -01° 57′
Magnitudes         A: 1.9    B: 3.7    C: 9.6
Separation          AB: 2.2″      BC: 58.0″
Position Angle    AB: 166°   (WDS 2012)  BC:  10°  (WDS 2006)
Distance: 818 Light Years
Spectral Classification: O9.5
Status:  AB is physical, orbital chart and data can be seen here.

Rich, one of the people who have commented on a few of these posts, mentioned Alnitak in one of his replies.  I had forgotten it was a double until I read his comments, so I took a close look at it on that full moon night, and had no problem seeing what turned out to be the “C” component situated about a full arcminute to the north of Alnitak.  I’ve seen it numerous times before – despite the glare, it’s far enough away to not really be that much of a challenge.   The next day, I was checking the Haas book and found the much closer “B” component, which I hadn’t noticed that night.  I went back through some sketches I did a few years ago, and sure enough, there it was — got it on January 16th of 2008 with a 7mm Nagler (126x) in a four inch refractor, as shown in the accompanying reproduced sketch.  My notes show “A” and “B” were touching, so I didn’t actually get a clean split — but I saw it, which was what interested me the most.

When I look at Alnitak, the color I see is bluish-white — period.  But apparently a lot of other people don’t — or haven’t.  Haas decribes the two brightest components as “yellow and silvery yellow.”   Burnham wrote that they have been called “topaz yellow and light purple,” “yellow and blue,” and finally — at last someone who almost agrees with me — “brilliant white.”  I’ll just leave you to work it out for yourself. 😉

To digress a bit, if you’re not familiar with this area of Orion, you’re in for a treat if you happen to be sitting behind a telescope on a dark, moonless night — certainly not this one!  If you move Alnitak to the west edge of your eyepiece, and then push it beyond the field of view, you should be able to glimpse the Flame Nebula (NGC 2024), a dark glowing cloud of gas that is pretty much split down the middle.  When the moon is turned off, my skies are about sixth magnitude, and rare is the dark night when I can’t see that dark, mysterious cloud.  If you live in a light polluted area, I suspect it’s probably rather elusive unless you use a filter of some kind — either an OIII or a UHC is recommended.

Sigma (σ) Orionis (Σ 762)              HIP: 26549    SAO: 132406
RA: 05h 38.7m   Dec: -02° 36′
Magnitudes       AB: 3.8    C: 8.8    D:  6.6     E: 6.3
Separation         AB-C: 11.4″          AB-D: 12.8″        AB-E: 41.2″
PA     AB-C:  238°  (WDS 2008)    AB-D:   84°  (WDS 2011)    AB-E:   62°  (WDS 2011)
Distance: 1148 LY
Spectral Classification: O9.5 (A)  B2 (B)

Σ 761           HIP: Not assigned in Simbad    SAO: 132401
RA: 05h 38.6m   Dec: -02° 33′
Magnitudes:         A: 7.9    B: 8.4    C: 8.6
Separation –        AB:  67.8″     AC: 71.8″   BC:  8.5″
Position Angle –  AB: 203°   AC: 209°    BC: 269°  (All WDS 2011 data)
Distance:  ?????
Spectral Classification: B5

Now, if you move one degree south of Alnitak to the area of the elusive Horsehead Nebula (B33), and then west another half degree, you’ll come to the quintuple star Sigma (σ) Orionis, and in the same field of view you’ll find the triple system Σ 761.  Sigma (σ) dominates the view, but the close “BC” pairing in Σ 761 will also catch your eye.

When I’m traveling through the territory of the Horsehead or the Orion Nebula, I always pull over for a few minutes and take a look at these two systems.  This night was no exception.  Despite the nearby moon, I had no problem seeing all of the components of these two multiple stars in my five inch refractor, except for the AB pairing of Sigma, which is a mere .25″ apart – for that you need a much larger scope than 99.9% of us have.

The seeing was steady enough to support a 12.5mm Ortho (94x), yielding a very well-resolved view of Sigma’s (σ)  four components, similar to what is shown in the accompanying sketch I made a few years ago.  As I looked at them, they reminded me of a small open cluster, and according to Kaler, they actually are part of a cluster that lies at a rough distance of 1150 light years.  The higher magnification of the Ortho also gave me a much wider view of the close “B” and “C” components of Σ 761 than I am accustomed to.  Normally if I’m in this area, it’s because I’m trying to pry the mysterious dark Horsehead Nebula out of the never-quite-dark-enough background sky, which calls for quite a bit less magnification.   A good test of your visual acuity and the optics of your scope is to see how low a magnification you can use and still split this “BC” pair.

If you get a chance to look at these two systems under moonless skies and away from city lights, you’ll find the brighter components of Sigma (σ) are like white jewels gleaming on black velvet, and the fainter components of both it and Σ 761 are sharp pin holes of light shining through from the other side.

As I normally do when I’ve wrapped up for the night — usually morning, actually — I grab my four-legged companion’s leash and let him take me for a walk.  So off we went at 2AM — he was sniffing the ground, and I was looking skyward sniffing for moon dust.  By now the moon was high overhead and it was almost as bright as daylight.  Even though I’ve described the winter full moon rather harshly here, I’m not so hopelessly hypnotized by starlight that I can’t recognize the beauty of a night like this.  There are times when you have to remind yourself to get away from the magnified view for a while and enjoy the night by taking a look around —– at the soft moonlit shadows, the hazy indistinct outline of the hills in the distance, the stands of trees that merge into a single dark silhouette projecting skyward, and the other-worldly beauty of a moonlit sky punctuated by a few flickering bright stars.

This was a night that was made for walking, not trying to ferret out faint stars lying impossibly close together in a bright sky.

And that’s what we did for about thirty minutes.

Horsing Around in Equuleus: Delta (δ), Σ 2786, Σ 2765, β70, and Lambda (λ)

Equuleus is one of those small and obscure constellations that is difficult to locate under the typical urban sky.   You really need  skies of at least fifth magnitude in order to pick it out visually, although binoculars will make the task much easier for people who aren’t that fortunate.   For a dedicated star-splitter devoted to ferreting out those poor double stars that don’t get much attention, it’s a happy hunting ground.  Provided, of course, the weather cooperates.  Which it hasn’t …. for quite some time, now.

Let’s start with the pronunciation, which is enough to throw you off this diminutive celestial horse before you even locate it —   Ee-KWOO-lee-us, which is Latin for Little Horse.  The name has been traced back to the Greek astronomer Hipparcos, of the second century B.C, although some accounts credit Ptolemy with it as well.

Equuleus in context. Click on the chart for a larger view. (Stellarium screen image with labels added)

You’ll find Equuleus wedged between Pegasus’ nose, marked by the star Enif, and another small but better known constellation, Delphinus.  Or  ……  you could follow these ancient directions included in Admiral William Smyth’s discussion of Delta (δ) Equulei on page 498 of his Bedford Catalog:

When Pegasus within our view,           his spacious square doth spread,
Midway from Markab to Altair                 you’ll find the Horse’s head.”

There is only one constellation smaller, Crux, in the southern hemisphere, which makes Equuleus the smallest in the north.  Credit goes to the Night Sky Observer’s Guide, Volume Two, for this information.

Now, back to the weather.  There are close to a dozen stars in Equuleus worth looking at, although several require good seeing because of their tight separations.  I had hoped to get enough cooperation from the weather to spend some time on all of them, but now that the November rains have started it looks like I missed the window of opportunity this year.  Even if it clears in the next couple of weeks, the moon will make it difficult to do much here, so for now, I’ll stick with mainly the northern part of the constellation and save the southern half for a later time.

We’ll start with Delta (δ), located at the northeast corner of the constellation, and use it as a jumping off point.  And, as we go through the rest of these, you’ll see that in most cases there isn’t much separation between these stars.

That’s because this is a small constellation and there’s not a lot of space.  😉

Screen shot from Stellarium with labels added. Click on this and the photos below for a larger view, and click a second time to enlarge once more.

Delta (δ)  (Σ 2777)  (H IV 37)         HIP: 104858    SAO: 126643
RA: 21h 14.5m   Dec: +10° 00′
Magnitudes: 4.5, 10.2
Separation:  74.3″
Position Angle: 6°   (WDS 2011)
Distance: 60.3 Light Years  (Simbad)
Spectral Classification: F6, F6

October 13th, 9PM I was using two scopes on this particular night, an Astro-Tech 90mm f/6.7 APO and a Zeiss 63mm f/13.3 achromat. At first I needed to use averted vision to see the secondary because of the wide magnitude difference between the two stars, but once I picked it out of the glare, I had no problem seeing it in either scope with direct vision.  The 90mm did well with a 16mm Meade SWA (38x) in it, and I gave several eyepieces a try in the Zeiss – the 16mm Meade (53x), a 12mm Radian (70x), and a 7.5mm Tak LE (80x).  The primary star is white, but the companion was far too faint for me to detect any color.  With his 5.9 inch refractor, Admiral Smyth saw the primary as “topaz yellow” and the secondary as “pale sapphire” — judgement withheld for the moment on that last one.   On the east side of the low power eyepieces, I noticed an eye-catching asterism of three ninth magnitude stars lined up in a north-south direction, which added a little something extra to the scene.

Σ 2786        HIP: 105295    SAO: 126707
RA: 21h 19.7m   Dec: +09° 31′
Magnitudes: 7.5, 8.2
Separation:  2.7″
Position Angle: 189°  (WDS 2011)
Distance: 605 Light Years (Simbad)
Spectral Classification: A3

Now we’ll move one degree to the southeast — this is kind of like a small town, everything is within walking distance — to Σ 2786, which should easily be visible in your finder when Delta is centered.

Gloss white, or pale white, this pair dominates a faint field. (East & west reversed to match the refractor view, click for a larger version)

October 29th, 9:00 PM This pair is much tighter than Delta, so it requires a bit closer scrutiny at first.    On this particular night, I was using my five inch Meade refractor.  It was an easy split with a 16mm eyepiece (53x), but I found the view through a 12mm Radian (98x) was the better of the two.  Both of these stars are similar in brightness, although a closer look reveals that “B” is just a bit fainter.  Haas describes them as “gloss white” – I saw a pale white without the gloss.  This one is a pleasing sight in a five inch scope, but probably less so in a 60 to 80mm, although it would be worth the effort to attempt to separate them at those apertures.

Σ 2765   (H I 63)          HIP: 104570    SAO: 126601
RA: 21h 11m   Dec: +09° 33′
Magnitudes: 8.47, 8.50
Separation:  2.8″
Position Angle: 78°  (WDS 2011)
Distance: 495 Light Years (Simbad)
Spectral Classification: A3

Now we’ll go back to Delta (δ), move one degree to the west with a slight tilt to the north, and find ourselves at fourth magnitude Gamma (γ), which again should be easy to see in your finder when Delta (δ)  is centered.  Gamma (γ)  is also a double, with a tight separation of 1.5″ — and, since the seeing hasn’t been that good in these parts for a couple of centuries, we’ll skip it for now (but if you succeed with this one, by all means let me know!).  You’ll notice a sixth magnitude star clinging to its southeast side, though, and if you follow that line half a degree further, you’ll come to Σ 2765.  Actually, the view of Gamma (γ) and that close sixth magnitude star, with Σ 2765 in the same field, is one of the highlights of this star-hopping tour.

I was able to get a look at these on two different nights:

I was able to squeeze pale white out of this close, dim pair of stars in a four inch refractor. (East & west reversed, click to enlarge)

October 13th, 9:30 PM This pair has the same 2.8″ separation as our previous pair, but is a bit fainter, although both stars are almost of equal magnitude.  Using the 90mm APO, I needed a 5mm Tak LE (120x) and a 4mm AT Plossl (150x) to see black space between them.  I was just barely able to split the pair in the Zeiss 63mm with a 10mm Radian (84x), but the seeing had deteriorated in the interval between scopes and it was much harder to get it to come to focus.  My notes for that night describe them as very close together and too dim to detect any color.

October 29th, 9:30 PM This time I used the AR-5 and was able to get a split at less magnification using the 16mm Meade SWA (74x), but it was very tight.  The separation was more pronounced in a 10mm Radian (118x), but I preferred the view in an 11m TV Plossl (107x), mainly because it looked better in the smaller field of view.  Seeing conditions, however, were going south quickly once again, so I moved on.

β70  (Bu 70)            HIP: 104035    SAO: 106818
RA: 21h 04.6m   Dec: +12° 01′
Magnitudes      AB: 7.72, 9.80     AC: 7.72, 11.2      BC: 9.80, 11.2
Separation:      AB: 81.3″            AC: 74.4″             BC: 8.9″
Position Angles:   AB:  241°    AC:  237°    BC:  96°   ( All data WDS 2012)
Distance: 659 Light Years  (Simbad)
Spectral Classification: “A” is K0, “C” is G5
NOTE: Magnitudes are from Simbad, not WDS

Now you wouldn’t think it would be possible to get lost within the confounded confines of this very small constellation … but it is.  Or at least I did.  More than once.

Your star hop to β70 can be made a little easier by starting at 18 Delphini. There is a line of three stars — HIP 103869 (magnitude 8.1), HIP 103858 (magnitude 7.2), and HIP 103730 (magnitude 7.7) — that lie about two thirds of the distance (about a degree) to B70. (Stellarium screen image with labels added, click to enlarge)

This little devil is very hard to find.  Delta (δ) and Gamma (γ) form a line that points west to 5.5 magnitude 18 Delphini, so the best way I’ve found to locate β70 is to start by moving Gamma (γ) over to the east side of your finder until you can see 5.5 magnitude 18 Delphini come into view three degrees to the west.  β70 is midway between Gamma (γ) Equulei and 18 Delphini, and about two degrees to the northeast of the line that joins those two.  If you picture an equilateral triangle with the last two stars at the east and west edges, you should see β70 at the apex of the triangle – not perfectly equilateral, but darn close. However, there are a few other faint stars right near it, so it’s easy to pick the wrong one.  Go for the brightest of the bunch and you should have it.

The elusive β70 (BU70) of Equuleean fame (STScI photo)

The first time I looked at this one, I made the mistake of thinking I had separated the two very close “B” and “C” components.  I’ve included a photo of the area, which shows them separated, as well as a fainter star just to the southeast of them.  It was that fainter star that I thought was the “C” part of this system because I couldn’t see the split in what was actually the “BC” pair.  I was using the 90mm APO and the Zeiss 63mm, and neither of them showed it at the magnifications I was using.  Actually, if the search hadn’t warped my usual discerning gaze, it would have dawned on me that I wasn’t likely to split that 5.3″ pair of tenth magnitude stars with those two scopes.

What made β70 so hard to find was that the PA’s don’t quite match when the wrong star is substituted for “C,” so I kept looking past my actual target for something that was a closer match.  Rather a humbling experience.

However — I went back on October 29th with the AR-5 in hopes of splitting the real “BC” pair — but by the time I got to β70, a dense fog creeping up out of the Pacific had removed it from view.  So, until next year ………….

And, if you’re wondering what the β in β70 stands for, it’s for S.W. Burnham, who discovered this terrible triple.

(Stellarium screen image with labels added, click to enlarge)

Lambda (λ)  (Σ 2742)
HIP: 103813    SAO: 126482
RA: 21h 02.2m   Dec: +07° 11′
Magnitudes: 7.4, 7.6
Separation:  2.9″
Position Angle: 214°    (WDS 2011)
Distance: 264 Light Years  (Simbad)
Spectral Classification: F8

And now for something completely different – and the best view of the whole tour.  We’re going into the far southern reaches of Equuleus, which will take us a distant three degrees to the south.  Going back to Gamma (γ), extend a line to the southwest until you reach Epsilon (ε) Equulei.  Move southwest three degrees along that line, which is not quite two-thirds of the distance to Epsilon (ε), and you should see Lambda (λ) about thirty arc minutes to the west of it.  If you’re not sure you have the right star, note that it’s the southernmost of a line formed by it and two other seventh magnitude stars pointing to the northwest.

“A very neat double star closely preceding the Horse’s nose . . . both white”  was Admiral Smyth’s impression of Lambda (λ).  I saw a very tight pair of equal magnitude stars with a distinctive yellow color that made them easy to pick out from the surrounding field. Haas describes these as a close copy of Gamma (γ) Virginis, better known as Porrima. Although quite a bit fainter, they warrant the comparison, provided you use enough magnification to split them cleanly.

I saw these as yellow in October of 2010, but eleven months later they appeared to be a pale white. So take your pick! (East & west reversed, click to enlarge).

October 13th, 9:45 PM I was almost able to separate them in the 63mm Zeiss using the Meade 16mm SWA (53x).  I swapped that out for a 14mm Radian (60x) and got a clean split, and then did a bit better with a 12mm Radian (70x).  In the 90mm f 6.7 APO, I couldn’t quite get them using a 10mm Radian (67x), but moving up to a 7.5mm Tak LE (80x) did the trick.  I gave a 5mm Tak LE (120x) a try, but poor seeing sent me back to the 7.5mm eyepiece.  Long focus refractor afficianados take note: the 63mm Zeiss split this pair with less magnification than the 90mm APO.  I suspect the much wider field of the shorter focal length APO had something to do with that – the more narrow field of the Zeiss narrows your zone of concentration to a much smaller area.

October 29th, 9:45 PM Back again, and this time with the AR-5 under much worse seeing conditions, but I was still able to pick out both stars with the 16mm Meade SWA (74x).  Because it worked so well on Σ 2765, I used the 11mm TV Plossl (107x) again, and got a great view and a clean split.  I also had an 80mm f15 out that night and was just able to detect both stars with the 60mm Meade SWA (75x).  By that time, the seeing had once again become too poor to use more magnification.

So that’s it for Equuleus this year.  I’ll be back next year for the southern half, which for those keeping track, will consist of Beta (β), S 781, and Epsilon (ε)– and also, I hope, much better seeing.

Until then, Clear Skies!

(WDS info updated 12/5/2014)

Cephean Siblings: Σ2840, OΣ 480, OΣ 486, Σ2872, and S800

Sometimes it’s amazing what you can find in a small area.  Greg and I have hit all the double star highlights in Cepheus – I think – but there are a whole more in this constellation that merit at least a look.  You’re not going to jump up and down and holler loud enough to wake up the neighbors at 3AM — if you do, leave me out of it, please — but if you approach this as an exercise in sharpening your star-hopping skills, you should be pleased with what you find.  Don’t expect a riot of color in any of these, but do expect to hone the subtle sensitivities of your visual apparatus.  🙂

Stellarium screen image with labels added, showing the locations of all the stars on our tour. Click on this or any of the other images for a larger view, and then a second time to enlarge it once again.

We’re going to use Delta (δ) Cephei as a base, because it’s easy to find and is centrally located in relation to these stars.  If you haven’t looked at this star, spend some time taking in the beautiful reddish-orange of the primary and the delicate blue of the secondary.  When you’ve done that,  we’ll get started by hopping off to the southwest.

Chart 1, showing Σ 2840 and Σ 2872. (Stellarium screen image)

Σ 2840  (H IV 79)         HIP: 107930    SAO: 33819
RA: 21h 52.0m   Dec: +55° 48′
Magnitudes: 5.6, 6.4
Separation:  18.1″
Position Angle: 196°  (WDS 2011)
Distance: 643 Light Years
Spectral Classification: B6
Status: The 5.6 magnitude “A” component is a spectroscopic binary

October 3rd, 1 AM:    This eye-pleasing double lies about five degrees (the average width of an 8×50 finder) to the southwest of Delta (δ).  If you’re star hopping — and I hope you are, you’ll never learn where things REALLY are any other way! 😉 —  move a distance of two degrees from Delta (δ) to Epsilon (ε) Cephei, and then continue another three degrees to the southwest and Σ 2840 will come into view in the finder.

Σ 2840 (STScI photo)

This pair lies in a rich star field, but when viewed through the eyepiece of a telescope, you’ll find them surrounded mainly by blackness, which has the wonderful effect of drawing your eye right to them.

Using my 60mm f/16.7 refractor and a 25mm Plössl (40x), I could see two white dots, one slightly brighter and larger than the other.  I took a look at it also in my Antares 105mm f/14.3 refractor with an 18mm Radian (83x), but found I preferred the view in the smaller scope — to my eyes the two stars are just more satisfying when seen closer together.   Not sure what that says about my eyes or taste — but I’m stuck with my eyes, and there’s no accounting for taste.

OΣ 480 Cephei (STT 480)   (No HIP assigned)     SAO: 34785
RA: 22h 46.1m   Dec: +58° 04′
Magnitudes: 7.6, 8.6
Separation:  30.6″
Position Angle: 117°  (WDS 2010)
Distance:  ?????
Spectral Classification: F8

Chart 2, showing OΣ 480 and OΣ 486 (Stellarium screen image)

October 3rd, 1:30 AM:     Now return to Delta (δ) Cephei and prepare to move east.  About one degree to the east of Delta (δ) you’ll see a line of three almost evenly spaced seventh magnitude stars running from the northeast to the southwest.  Center the middle one in your finder, then move another degree east and you’ll see two sixth magnitude stars lying at the same angle.  Center the southern-most of the two, and you’ll see OΣ 480 lying to the southeast, right at the western edge of a cluster of stars.

These are perfect for a 60mm scope – I used a 26mm Plössl for 39x and found two easily separated stars, one a bit brighter than the other, staring back at me.  Haas describes them as “lemon white, azure white,” but they were really too faint for me to describe them as anything other than a faint white.

OΣ 480 (STScI photo)

These two stars lie right at the edge of an open cluster, NGC 7380, which is slightly oval in shape.  I counted about twenty stars in my 105mm scope using an 18mm Radian (83x).  There is an area of nebulosity, SH2-142, associated with this cluster, which was easily seen in both the 105mm and the 60mm scopes.  I was enjoying a moonless night with excellent transparency, but was still surprised by how well the nebulosity could be seen in the 60mm scope at 39x.  The Night Sky Observer’s Guide comments that an OIII filter really isn’t necessary to see the nebulosity — and obviously, they’re correct!

This is heaven — a few wisps of nebulous clouds entwined in a small cluster of stars, with a small pair of pinpoint sharp, white stars at the edge.  I had to restrain myself from waking up the neighbors.

OΣ 486         HIP: 113853    SAO: 20393
RA: 23h 03.4m   Dec: 60° 26.7′
Magnitudes: 6.7, 9.5
Separation:  35.2″
Position Angle: 276°  (WDS 2006)
Distance:  1930 Light Years
Spectral Classification: B2
Status: The 6.7 magnitude “A” component is a spectroscopic binary

October 10th, 12:30 AM:     Now, don’t move your scope yet! – even though I did. To get to our next pair, we’re going to start from OΣ 480 (see chart number two above) and move one degree northeast to a triangle of seventh and eighth magnitude stars.  From there, continue another two degrees along that same line and OΣ 486 should be the brightest star near the center of your finder.

OΣ 486 (STScI photo)

This is a fairly wide pair and easy to split.  I could see the faint 9.3 magnitude companion in the 105mm scope using an 18mm Radian (83x) with no problem, but I needed to use averted vision in the 60mm equipped with a 17mm Plössl (59x) to detect it.  It lacks the added interest of being right at the edge of an open cluster, as was the case with our previous pair, OΣ 480.  However, NGC 7510 lies a bit less than a degree to the northeast, so if you’re using an eyepiece with a field of view of about one and half degrees, you should see it at the edge of your eyepiece while OΣ 486 is centered in it.  It’s a tight little cluster of about four arc minutes in diameter which is listed at a magnitude of eight, so don’t expect to see the Pleiades!   I could resolve about a dozen stars in the 105mm at 83x, with the fainter members adding a nebulous glow to the background.

Σ 2872 (22 Cephei)  (H IV 126)    (No HIP number assigned)     SAO: 34101
RA: 22h 09m   Dec: +59° 17′
Magnitudes: 7.1, 8.0
Separation:  21.7″
Position Angle: 316°  (WDS 2008)
Distance: ?????
Spectral Classification:  B9.5

October 10th, 1AM:     OK – back to Delta (δ) again on chart number one above!  We’ll start by moving two degrees west to Zeta (ζ) Cephei (also known as 21 Cephei) and then one degree north — with a slight bias to the west — and you should have Σ 2872 in your finder, with the brighter fifth magnitude Lambda (λ) Cephei lying just to the east of it.

In the 60mm scope using a 26mm Plössl (39x), I found two white dots very close to each other, one barely brighter than the other.

Σ 2872 (22 Cephei) (STScI photo)

A  17mm Plössl (59x) separated them just far enough to make a very attractive pair.  Switching to the 105mm refractor, an 18mm Radian (83x) gave me a view similar to that in the 60mm at 59x, but significantly brighter.

This pair is located in a rich star field, but as was the case with our first pair of doubles, Σ 2840, the view in the eyepiece reveals the immediate area surrounding them to be almost devoid of stars.  If you move your scope about 3/4 of a degree (45 arc minutes) to the northwest, the beautiful and very interesting quintuple star OΣ 461 (15 Cephei) will come into view.

S 800         HIP: 108073    SAO: 19718
RA: 21h 53.8m   Dec: 62° 37′
Magnitudes: 7.1, 7.9
Separation:  62.6″
Position Angle:  145°  (WDS 1999)
Distance:  2346.5 Light Years
Spectral Classification:  B1

Chart number 3, showing S 800 (Stellarium screen image)

October 10th, 1:30 AM:     And now for something completely different — a new starting point!   I got lost more than once trying to find this one until I finally got smart and decided to search for it by starting instead at 4th magnitude Xi (ξ) Cephei, which lies almost right in the middle of the rectangular shape formed by Alpha (α), Beta (β), Iota (ι), and Zeta (ζ) Cephei  (see the chart at the beginning of this tour).

S 800 is located two degrees to the southwest of Xi (ξ), but the easiest way to get there is to first move directly south 1.5 degrees.  This will bring you to a north-south line of three fifth magnitude stars, which are 18, 20, and 19 Cephei, in that order.  Center your finder on the middle one, 20 Cephei, (it should already by pretty close) and move west one degree and you’re there.

S 800 – NGC 7160 (STScI photo)

Now what we have this time is a double star right in the middle of a small open cluster, NGC 7160, measuring about six minutes in diameter — and in the 105mm scope that’s exactly what it looks like – but no nebulosity this time.  In addition to the two stars of S 800, there is a faint pair of 10th magnitude stars slightly to the northeast and a trio of ninth magnitude stars to the southwest, which are the brighter members of this faint cluster.

S 800 is a tight pair in the 60mm scope at 39x using a 26mm Plössl, but is much improved after moving up to a 17mm Plössl (59x), and is a very pleasant sight in the 105mm scope using a 14mm Radian (107x).  Haas describes them as “pure-white and green-white” – I agree with the white, but couldn’t detect the green.

And now, if you’ve done all this in one night, sit back and take a break, and think about what you’ve seen — five pairs of double stars, three of them located at the edge, or not far from, or in the middle of open clusters, and two completely surrounded by almost nothing but black space.  And even though we’ve stayed within a square of about eight degrees of dark sky, we’re stuck out here at S 800, a distance of just over 2346 light years from home.  So you should be tired!

And if you’re not, you sure will be by the time you get there.   😎

Patrolling in North Perseus: Gamma (γ) Persei, Σ331 (STF 331), and Theta (θ) Persei

When the moon lights up the sky, the best place to look for double stars is as far away from it as you can get — and of course, if the sky is full of moonlight, you can just about bet it will be clear!  So, with the moon about 70% of the way to being full in the middle part of October, I turned to the north and found a splendid grouping of stars in a rather small area at the northern tip of Perseus.  One of that grouping is Eta (η) Persei, which you can find described here, and the others are discussed below.

Gamma (γ) Persei  (h 2170, or HJ 2170 in the WDS)       HIP: 14328    SAO: 23789
RA: 03h 4.8m   Dec: +53° 30′
Magnitudes: 2.9, 10.8
Separation:  55.3″
Position Angle:  329°  (WDS 1998)
Distance:  256.4 Light Years
Spectral Classification:  G8, A2

My first look at Gamma (γ) Persei was on October 18th at about 10 PM, when I was poking round Perseus with my six inch f/10 refractor and a 60mm f/15 that is mounted on the back of it.  The moon was at my back, and unlike the previous night, there was no haze in the sky, so the transparency was pretty darn good.

Stellarium screen image with labels added – click on the image for a larger view.

As you can see on the map above, Gamma (γ) is located at the eastern corner of three stars that form the small triangle at the top of Perseus.  I dropped an 18mm Radian (84x) into the focuser of the six inch scope, pointed it up into the northern sky, centered it in the finder, adjusted the focuser, and found a beautiful deep yellow primary.   The 10.8 magnitude of the secondary means it’s 7.6 magnitudes fainter than the primary — meaning it emits about 1100 times less light — so between the yellow glare from that brighter component and the bright sky background, I had to look hard to find what I was looking for.  Finally, after several attempts, I spotted it with averted vision.  I’m sure it would be much easier on a dark night, but I suspect even then it would be difficult to pick up in the 60mm scope.  In keeping with the difficulty of finding it, “B” is classified as a white dwarf.  But even at that, it still has a mass 1.9 times greater than our sun.  Surprisingly, “A” is not much more massive at 2.5 times that of the sun.

Σ 331  (H III 36)          HIP: 14043    SAO: 23765
RA: 03h 00.9m   Dec: +52° 21′
Magnitudes: 5.2, 6.2
Separation:  11.9″
Position Angle:  85°  (WDS 2011)
Distance:  795.5 Light Years
Spectral Classification: B7

Moving a full degree to the southwest we come to Σ 331, which Haas describes as a showcase pair.  I looked at this pair on the night of October 17th with an 80mm f/15 refractor and a 127mm Meade AR-5.  In the 80mm, using a 20mm Plössl (60x), I found the two stars were barely separated, so I switched to an 11mm Plössl (109x) to put some distance between them.  The view was pleasant, but there was a lot of moisture in the air which was busy reflecting the moon’s bright light, so the 80mm really was not the best choice for these two on this particular night.

I switched over to the 127mm scope, started with an 18mm Radian (66x), and then moved up a bit in magnification to a 14mm Radian (84x) — and found this pair living up to Haas’s description of them.  The primary was a bright white; the secondary I saw as blue.  Haas describes them as “lemon white and dusty blue-green,” so our descriptions are close, but I didn’t see any dust — just a lot of bright moonlit haze.  She notes that Webb described them as white and blue, so maybe my eyes are sensitive to the same spectral wavelengths as his eyes were.  At any rate, these two stars are rather pleasing, even in a bright sky, so I’ll come back to them when the skies are dark.  Bright moon or not, it’s worth spending some time soaking up the colorful view of this pair.

Theta (θ) Persei  (Σ 296)  (H III 58)         HIP: 12777    SAO: 38288
RA: 02h 44.2m   Dec: +49° 14′
Magnitudes  AB: 4.2, 10.3    AC: 4.2, 11.0
Separation   AB: 20.3″           AC: 94.3″
Position Angles    AB: 304°  (WDS 2007)    AC: 243°  (WDS 1999)
Distance:  37 Light Years
Spectral Classification:  F8 (A), M2 (B)

As we move three degrees further to the southwest to reach Theta (θ) Persei, we go past Tau (τ), a very close double with magnitudes of 7.0 and 7.3, separated by 1.5″.   I couldn’t resist taking a look, even though I doubted I could split them in the 127mm scope that night.  And of course I didn’t — the seeing was nowhere steady enough for that.  Then my attention was diverted elsewhere — I don’t remember where, but probably to the jovian delights of Jupiter — so it was the following evening, October 18th, that I got back to Theta (θ), using my six inch and the 60mm described above under Gamma (γ) Persei.

Theta Persei and its components – click on image for a larger view. (STScI photo with labels added)

In the six inch f/10, using an 18mm Radian (84x), all three of the components came into view instantly.  In the 60mm, on the other hand, I wasn’t able to pick 10th magnitude “B” out of the glare of the primary, but I did manage to glimpse eleventh magnitude “C” with averted vision, thanks to its greater distance from the primary.  In the larger scope, these three stars form a long, extended right angle triangle.  “A” appeared to me to be pale yellow with a bit of white.  Haas calls it amber-yellow, and describes them as a “grand sight!”  They certainly are that in the six inch, and no doubt they would be even grander with a darker sky as a backdrop.  “B” is a red dwarf, but it was too faint, or the glare from the primary was too strong, to detect the red color.  There was no color to be seen in “C,” either, which according to Kaler is not actually a companion, but just happens to lie along our line of sight to Theta (θ).

So much for the Perseus in the moonlight.   Next stop, Perseus in no moonlight!

These observations were made on October 17th and 18th, 2010, under bright moonlight with no sunglasses, and with the following telescopes: an old 80mm f/15 refractor with a Carton lens, my dependable 127mm f/9.3 Meade AR-5, a 152mm f/10 custom built refractor hailing from the wild reaches of southwestern Ohio, and my home made 60mm f/15 refractor mounted on top of it.

More information on Gamma (γ) and Theta (θ) Persei can be found by clicking on the links to Jim Kaler’s Stars Site!

Eta (η) Persei: A Persean Puzzle

The northern tip of Perseus is a great location for tracking down several splendid multiple stars — and right at the top of the Persean peak is where you’ll find Eta (η) Persei.

Stellarium screen image with labels added — Eta (η) is at the top left in this view. Click on image for a larger view.

My first look at it came on September 25th in a 90mm f/10 refractor.  Using a 12.5mm eyepiece (73x), I found the primary was a splendid yellow-red, but couldn’t really detect any significant color in “B.”  I was using the Haas book, which only lists data for the “A” and “B” components.  But I noticed several faint stars rather close to the the primary, so I checked the Night Sky Observer’s Guide (scroll down a bit to see the reference) and sure enough, I found a third component listed there, “AC”.  The data also includes a “CD” component, but at magnitudes of 9.8 and 10.3 with a separation of five arc seconds, I skipped them, deciding those two were very likely to be lost in the glare of the primary.  (Note of 10/5/2014): The magnitudes of 9.8 and 10.3 for the CD pair turned out to be inaccurate — we’ll get to that in just a moment).

Eta (η) Persei    (Miram)   (Σ 307)           HIP: 13268   SAO: 23655
(AB is H IV 4, AC is H VI 21)
RA: 02h 50.7m   Dec:+55° 54′
Identifier	Magnitudes	Separation	Position Angle	WDS
STF 307     AB:	3.76,   8.50	31.40″	295°	2012
STF 307     AC:	3.76, 11.61	64.00″	269°	2014
SHJ 34       AE:	3.76,   9.24	242.90″	297°	2012
WAL 19      AF:	3.76, 11.44	57.40″	24°	2012
WAR 1       CD:	11.61, 12.70	5.10″	116°	2012
Distance: 1331 Light Years
Spectral Classification:   A: M3 or K3     B: A0       C: B        E: A2

So, back again on October 17th with the bright moon at my back – but doing it’s best to shine into my eyepieces – I went in search of “C” using a bit more aperture, a Meade five inch refractor.  This time I found the primary had a dark  golden hue tending toward red and “B” was clearly blue.  I also noticed that “A” and “B” pointed to the middle of three stars which formed the top of a nice “T” just to the west of Eta (η) and its companions.  The moon was illuminating a bright haze in the sky, so transparency was not the best.  There was only one star near the primary that was close to the 9.8 magnitude listed for “C,” but in order to match up with the published data, the position angles of “B” and “C” would have to be reversed.  Since there was nothing else to be seen in the right places, I felt pretty sure that was what had happened.

But not sure enough to bet the farm on it — or a telescope.  So I went back the next night with the big gun, my six inch f/10 refractor, and took another look — the sky was still bright, but the haze was gone, so the transparency was much better.  With averted vision, I could just barely detect a star very close to the published position angle for “C” — but it was a whole lot fainter than the 9.8 magnitude that was shown for it.

(Another note:  This was written in October of 2010 when the magnitude for “C” was shown as 9.8.  As of 10/5/2014, the WDS has updated the magnitude of “C” to 11.61, which is a much better match with what I saw in the six inch refractor.  As a result, much of what follows no longer applies, but it’s still provides an interesting look at the process of discovery we all go through as we learn about double stars.  There’s a message here:  nothing stays the same forever, including stars!  For another look at Eta Persei, read this post which was written two years later).

Eta (η) Persei and magnitudes of surrounding stars. Click on image for a larger view.

After checking various places to see what I could find, I found that the situation is about as clear as meandering mud in a Martian moraine.  What it seems to come down to is that there isn’t a 9.8 magnitude star at a position angle of 268 degrees.  I made a sketch which is reproduced here and have labeled the magnitudes of most of the stars in it.  What it shows is a magnitude 11.5 star at about 280 degrees that is about thirty arc seconds past the 66.6″ shown for “C,” and a 13.4 magnitude star that is very close to the published 268 degrees and also is at about the correct distance.

So which one is the real “C”?  Is it a variable star?  Has its light been dimmed by a cloud of that ubiquitous dark matter that no one has been able to identify yet? 😉   I don’t know, but after reading Jim Kaler’s summary of Eta Persei, it appears that in all likelihood neither “B” or “C” are really gravitationally linked to the primary — “B” would have to be 11,500 Astronomical Units from the primary and would take 350,000 years to orbit it .  And to complicate matters, there are also “E” and “F” stars, which probably really are not components because they’re probably really not gravitationally linked either.  Clear as Martian mud.

Whatever the case, the “A” and “B” components of Eta (η) Persei are well worth taking a look at.  Haas describes them as 60mm showpieces, which they certainly are, and describes the colors as “apricot orange and cobalt blue.”

Not content to leave things where they were, I rolled out of bed at 5 AM on the morning of October 20th with intentions of taking another look at Eta (η), but this time under dark skies.  I was also after one last look at Comet Hartley-2 before the moon made it difficult to see for the next week.  Using an 80mm AT f/6 to look at the comet first, I found it right in the middle of Auriga and studied it closely for about fifteen minutes.  Then I pointed the scope up at Eta (η) Persei while the sky was dark, and again — with averted vision — I found the 11.5 magnitude star about where “C” was supposed to be, but again — it was too faint for me to be convinced it matched the 9.8 magnitudes listed for it.   And I knew the 80mm scope wasn’t pulling in the 13.4 magnitude star shown on the sketch which I had seen in the six inch scope.

No doubt I’ll return to Eta (η) Persei when the skies are dark and the weather cooperates, but daylight was due soon, so I moved on to other things.  I lingered over M42 and the Trapezium, swung up to the Pleiades, and could see that the sky was starting to brighten quite a bit.  I packed everything up, took it in the house, and grabbed my four-legged companion’s leash, and the two of us took a short walk.  Even though it was getting lighter, I couldn’t quit looking up at the sky because the crisp transparency made it absolutely irresistible.  After about a fifteen minute walk, we came back into the drive and I stopped to look up once again.  All the fainter stars were gone by that time, but all three of the stars in Orion’s belt could be seen, and I could still pick out about five stars in the Pleiades.  I watched those fade rather quickly and turned back to Orion.  Gradually each of the three belt stars were extinguished by our own star, then Betelgeuse became hard to see, and finally Rigel began to fade into the blue sky.

Daylight wasn’t going to be denied, but I really felt like I had been robbed of the stellar splendor of that beautifully transparent, star-filled sky I had spent the last two hours with.  Blue and cloudless at it was, the daytime sky just couldn’t match the awe I had felt under that black sky glowing with stars.

The observations of Eta (η) Persei were made on September 25th, October 17th, 18th, and 20th, 2010, with several refractors – an 80mm f/6 AT-LE, an Orion 90mm f/10, a Meade 127mm f/9.3, and a custom built six inch f/10.