DSC-60: Tackling Meissa with a 60mm SCT!

This is a DSC-60 Project observation –  for project details go here.

from Double Star Club list

[  ]

22

Lamda Orionis

05h 35m.1

+09° 56′

3.6, 5.5

4.4″

43°

from John’s post:

Meissa (Lambda [λ] Orionis)
RA: 5h 35.1m  Dec: +09° 56′
Magnitudes –  A: 3.5     B: 5.5     C: 10.7     D: 9.6
Separation –   AB: 4.9″      AC: 28.7″      AD: 78.0″
Postion Angle –   AB: 50°      AC: 185°       AD: 272°
Distance:  1056 LY
Spectral Classification –  A: O8  B: BO.5

So you didn’t know they made a 60mm Schmidt Cassegrain? Niether did I.  But if you have one of the ubiquitous 8-inch SCTs – hmmm, come to think of it, I have three –  you can make an off-axis mask for it and turn it instantly into a color-perfect, 60mm scope. The cost can be close to nothing, the time about half an hour, and, of course, you do no permanent injury to the scope – the mask is something you put on and take off like a lens cap. It just cuts the scope down to 60mm.  I’ll do a separate post on why and how, but the object here is to see how this performs on Meissa a really wonderful star in Orion’s head.

I just got out at 5 am this morning as astronomical twilight began and quickly swung my “parked” SCT  (it stays set-up in a little observatory) to Meissa. What a sight this is. I didn’t even try to split it at first. I just enjoyed the wide field view. And I did this without the mask on the SCT so I was picking up most of that wonderful pattern of stars that make’s up Orion’s head and is part of an obscure open cluster. (See John’s post for details and charts. )

I was using a 24mm Panoptic which yields 83X and roughly a  49-minute field of view.  I wanted more, but serious twilight was closing in and a wider field eyepiece was 100 feet away in the house, so I stuck with the 24mm Pan, absorbed the beauty of the scene, then popped in a 16mm Nagler. Yep. I could see some signs of a split, but the stars were pretty fiery. So I quickly put on the off-axis aperture mask. (The off-axis part is to avoid the central obstruction.)

Voila! I now had 60mm of clear, unobstructed, color-free aperture. And what a difference. Meissa and her brightest companion  – yes, we’re only going after the brightest companion because that’s what the DSC list calls for – and that’s what is easily in reach of 60mm of aperture.  (I stress “easily” because John is always pulling rabbits out of the hat with his 60mm scopes – secondary,  tertiary and whatever you call the fourth star in a multiple just tumble out of his scopes like clowns out of a tiny car in the circus.  Not me. I stick with the easy stuff, by and large. I don’t have John’s eyes,really dark skies, endless patience and observing skills.)

Anyway – these are the sights I love. I just wanted to sit there an absorb it.  A large, white dot tinged with blue, and next to it a fainter, smaller, violet dot. Simply lovely. I mean these were the kind of perfect, round, well-behaved 60mm stars that we thrive on. Such order has a special ascethic of its own. Wonder if I can split it witht he 24mm? Out came the 16mm (125X) and back in went the 24 Pan – and yes, sure enough,there they were. Absolutely exquisite in their delicacy.

And at higher power? Well with an 11mm Nagler (182X) we had a big old honking split.  Yes, skies were steady! And yes, this is too darned much power for a 60mm if you follow the rules, as I generally do, and limit yourself to 60X per inch (2.5X per millimeter)  then 144X should be tops. But the heck with the rules, what about the 9mm Nagler – 222X?  Yes! We certainly have lost light – and eye position becomes absolutely critical, but we still have a perfect pair of stars.

That eye position business is interesting. John and I both became acutely aware of it when we first experimented with masking. The reason for it is simple. The higher the power, the smaller the exit pupil – the cone of light exiting the scope – and so of your eye isn’t in perfect position you don’t see anything.  There’s a wonderful eyepiece calcualtor on the Televue web site which I use when I want data like this and going there I learned that the 16mm Nagler gave me an exit pupil of about half a millimeter with the scope masked  which is right at the limit of what any sensible person recommends. (Hey, that’s 125X and pushing real near to the 60X per inch limit. ) Televue recommends no more than 2.5X per mm which would put the top at 150X and the 13mm Nagler – next in my case – delivers 154X and that, for Televue, is too much. And keep in mind, these folks are in the business of selling us eyepieces – so i put a lot of stock in their recommendations wwhen they start telling me NOT to use certain eyepieces they make.

But . .. who can resist trying? So the 11mm delivered an exit pupil of .33mm and the 9mm of .27mm – ridiculously small cone’s of light. No wonder eye position was absolutely critical.  But this is of more than academic interest. I learned something from it this morning. Eye position is pretty darned critical when you are using full aperture, too!

Now it’s interesting, because you don’t hit the wall – half a millimeter exit pupil – until you put in a 5mm eyepiece into your  8-inch scope – I’m talking unmasked now. WIth 200mm of aperture the numbers change. Using the 2.5X per mm rule that Televue applies you should be able to use 500X. But Televue has another rule that cuts in before then – they recommend 350X as the maximum “regardless of aperture.”  Of course they’ll sell you eyepieces that will take you higher – at least on the typical 8-inch SCT –  but they won’t recommend you use them to deliver such power.

But here’s what I found as I went back to viewing Meissa unmasked: I could see perfect stars  in the 8-inch SCT this morning – conditions were very good – but only if I was very careful to get my eye centered perfectly over the eyepiece. I’m sure someone will tell me that’s because I need to be on the axis of the light cone, or something like that – and this is hardly an entirely new revelation. But quite honestly, before fooling around with masking I was more likely to assume that  when stars  misbehaved it was because:

a – I didn’t have the focus correct

b – seeing was too poor to deliver a sharp image

To these two obvious thing I now have to add eye position, which with my Naglers, at least , is critical. I could really get quite an attarctive  split this morning with quiet , well-behaved stars, at several different powers and full aperture IF I was very careful about eye position.  Not all that easy to do.  I always observe sitting down, of course, but to position your eye correctly you need to really be just at the right height above the eyepiece and  in this case I used a hand to form a brige between the eyepiece  and my face to help steady it. (OK – I’m 70 -maybe younger folks would find this easier.)

If I don’t do this, the view unmasked is pretty if you like dancing, flaming stars.  In between the flaring you do see the split – and the additional aperture does show you the fainter companions John describes – and with the wide field provided by the 24 Pan and bright stars provided by eight inches of light grasp, Meissa really is beautiful. But I am also sure that if I didn’t have such great seeing conditions I would not have seen it that way – the 60mm would have provided an improvement for seeing Meissa A and B as clean, steady, dots. (One  other possibility – the scope I was using is a Meade LT-8 ACF – the Advanced Coma Free variety.  Perhaps that contributed to the view – I just don’t know. It would have been fun to have it go head to head against one of my older SCTs without the advanced design.)

It’s a trap! No it’s THE Trap – the truly awesome Trapezium done DSC-60 style

Hubble photo of Orion Nebulae modifed to put emphasis on the Trapezium. Click on image for larger version.(Flipped left to right as in telescope using a diagonal.)

This is a DSC-60 Project observation for project details go here.

Double Star Club list:

Theta 1 Orionis

05h 35m.3

-05° 23′

6.7, 7.9, 5.1, 6.7

8.8″,13″, 21.5″

31° , 132°, 96°

Click for larger image.

Theta 1 Orionis (θ 1 ) – Trapezium 
RA: 05h 35.3m Dec: -05° 23′
Mag: 6.7, 8.0, 5.1, 6.7    Sep & PA: See graphic
Distance: 1350 ly
Spectral type: B1,B0,O6,B0.5

Magnitudes differ somewhat by source – these are from James Kaler and listed A-D, as are the spectral classes. A&B are eclipsing variables.

In my book there is simply no prettier, no more awe inspiring, no more intellectually stimulating sight in the heavens than the Orion Nebulae with the Trapezium at its heart. This four-star trapezoid is easily in reach of any small telescope and positioned near enough to the celestial equator so that it can be observed from just about any where in the world.

When I say this post is “done DSC-60 style”  what I mean is this post  will focus on the four stars in the Double Star Club list  and how they look through a 60mm scope. But these stars are easily reached by even a 50mm refractor.  In fact some say they can be seen with 10X50 binoculars held real steady. I can’t see them that way. My eyes need a 50mm objective and at least 20X to see three of the four stars.  And the sight only gets more interesting – because the surrounding nebula is enhanced – if you use a larger scope and there are two more stars in the Trapezium worth pursuing with larger instruments – and actually more still that are probably out of the reach of amateur observers.

But one of the first lessons the Trapezium offers us is the difference between the human eye and the camera. Look at just about any of the many gorgeous pictures of the Orion Nebula and you will not see the Trapezium no matter how large the telescope used.  You rarely see it in a photograph that even approximates the visual view through a telescope. It certainly doesn’t come through well in the Hubble photo that leads this post, though the nebula is spectacular. But at the telescope your eye will capture the glory of the nebula and the four diamond studs that are the Trapezium.

I’ve been looking at this off and on for more than a half century and it never grows dull, but the view through a 60mm refractor takes me back to my youth and sparks the love affair anew. Here are the pearls you seek – elegantly represented in an out-of-this-world setting. The “C” star glows brightest. I know, we’re used to the brightest star of a multiple star being designated “A,” but in the case of the Trapezium they broke this rule and lettered the brightest four stars in order of RA. The dimmer, more difficult E and F stars do not follow this pattern, however, but they’re out of reach of the 60mm scope so I won’t pursue them here.

Simulation of the low power telescope view of the Trapezium - with the Orion Nebula removed for clarity, but, of course, you will see it with binoculars or telescope. This small image is typical of what the naked eye reveals. Click on it to get a larger version showing the telescope view at low power.

With the naked eye or low power binoculars you see essentially two stars here – the Trapezium looking like one star identified as Theta 1 (θ 1 ) Orionis and what looks like it’s twin, Theta 2 (θ 2 ) Orionis.  Theta 2 is the brightest star in what I call Orion’s Mini-belt. These three stars will probably be the first to catch your eye in a scope and they point to the Trapezium which, of course, unfolds more and more as you increase power. There is about 134 seconds of separation between Theta 1 and Theta 2 – the stars of the Trapezium themselves span about 14-seconds of arc.

I had to play around with the preferences in Starry Night Pro making the stars into tiny specks and get rid of the nebula entirely  in order to simulate the view through my 60mm Unitron refractor at about 36X using a 25mm Ramsden eyepiece – yes, that’s one of the old eyepieces supplied with the scope c. 1970! Of course in the scope I see both the nebula and the Trapesium, so the simulation just can’t do the view justice. What a;ways missing in books and even on the computer screen is the brightness dimension – it gets represented – simulated – by the size of a dot indicating a star, but brightness isn’t size – its – well – brightness! And I think that’s why the live observing experience remains unique and important.

To me there is something magical in such a low power view where the stars are mere pinpoints. I liked this view also because it revealed the nebula for what it is – a burst blister in the surrounding darkness caused by the  huge star-forming region known as the Orion Molecular Cloud. That cloud is far, far larger than what I could see in the telescope field, covering roughly half the constellation of Orion.

I switched to an 18mm Kellner –  I was going completely “retro” on this evening, using the Unitron with its original eyepieces and original Unihex eyepiece holder which includes a less than pristine diagonal.  It just felt right to do this. At this power (50X) the brightness differences of the stars is more apparent and the C star really looks blue to me while across from it the B star still is just a pinprick. (While some have reported color in these stars I see them as white or blue, with duller shades simply a result of the star being fainter.)

Moving up to a 12.5 Kellner (72X) and a 9mm Symetrical (100X) the picture got bigger, but no brighter. Aesthetically I preferred the view at 50X. It had an elegance enhanced by the delicacy of the relatively  dim, B star.

But there are so many things to take in here that you need to just sit and stare and tell yourself what all of this represents. For many years, when confronted with this view, I dreamed of flying in a rocket ship to the Orion nebula – it’s a mere 1,350 light years away – and I imagined looking out the window and seeing these huge, glowing clouds pass by as you do in an airliner.  But the truth is the view would be more like what you see in the simuation above. There would be no clouds! this where the magician of reality  uses great distance to literally pull the wool over our eyes.

My bubble in this respect was broken by Terrence Dickerson in his book “Nightwatch” in which he wrote:

. . . a hypothetical spaceship rocketing through the nebula would encounter only slightly more particles than those recorded in interstellar space. The average density of the nebula is one-millionth the density of a good laboratory vacuum.

Of course it gets much denser near where new stars are forming, since they are pulling material together.

Does that diminish the viewing experience in any way? Heck no! It is a testimony to how distant 1,350 lights years really is. The numbers simply numb us – but try to imagine particles so far apart that there are far fewer of them than in a vacuum on Earth, then imagine us actually seeing them as clouds because we are so far away!

Of course,  the Trapezium at the heart of the nebula is exactly what it appears to be – four hot, young stars that have burned through the dust around them and popped a blister on the huge Orion Molecular Cloud, giving us a look at what is behind that cosmic screen.

And behind the scenes . . .

And then there is the incredible number of stars that are hidden by dust and need to be dug out with infrared observing tools and when they are what we find is the Trap is the tip of the iceberg – an iceberg that holds what is probably the youngest and defintely the most star-packed open cluster we know. The density of this star city is believed to be  6,000 stars per cubic light year – think of what that must be like in comparison to our own region where the nearest star is more than four light years away.  The age is believed to be less than a million years and the Trapezium itself is unstable and will probably vanish in a huge explosion of the C star in the next few million years – so get a look now while you can!

This is all part of what makes the  Trap and surrounding nebula a sight where the sheer majesty overwhelms you. I strongly urge you to click on the following picture to study the larger version. The picture is a composite of what is seen with the Hubble Space Telescope in Visible light and what is seen by the Spitzer Space telescope in infrared light.  As NASA explains it:

Orange-yellow dots revealed by Spitzer are actually infant stars deeply embedded in a cocoon of dust and gas. Hubble showed less embedded stars as specks of green, and foreground stars as blue spots.” All but washed out in the long exposure are the four stars of the Trapezium in the bright area below and to the right of center.

Click image for a larger version of this composite shot in visible light and infra red.

Go here for complete picture and NASA explanation.

Jim Kaler points out more fascinating facts within the Trap itself:

By far the leader of the pack is Theta-1 C, a great 40-solar-mass star with a temperature of 40,000 Kelvin (making it the hottest “naked eye” star, though the 4 are inseparable without optical aid), a huge luminosity 210,000 times that of the Sun (85 percent of the Trapezium’s total), and a 1000 kilometer/second wind with 100,000 times the flow rate of the solar wind. The power of the star is such that it is evaporating dusty disks around nearby new stars that in other settings might form planets.

The other members of the Trapezium pale only in comparison with “C,” all containing over 10 solar masses. A main interest lies in their multiplicity. Theta-1 A is an eclipsing double also known as V 1016 Ori. Every 65 days, the star dips by a magnitude as a star still in the process of formation just one Astronomical Unit away passes in front of the bright component, the whole thing watched by another companion 100 AU off.

Theta-1 D seems to have a companion as well. The champion in this contest, however, is Theta-1 B, which has a companion 60 AU away called “B1.” “B” itself is another eclipser (known also as BM Ori) that drops by nearly a magnitude every 6.5 days, the companion probably much like the Sun. Since “B1” is also double, Theta-1 B is quadruple. Adding them all up (and including fainter Theta-1 E, which lies close by), the Trapezium is a complex multiple of 11 stars!

. . .  Most multiple stars are hierarchical, a distant star going around a close double (like Theta-1 B), or two close doubles going around each other (like Mizar or Epsilon Lyrae), which gives great stability. The Trapezium, on the other hand, is gravitationally unstable, the stars all too close together. As a result, one after the other will be ejected from the group. After only a few million years, the leader of them all, Theta-1 C, will inevitably explode as a great supernova, the others probably doing so as well, all lighting the dusty gases of interstellar space, all providing shock waves that will promote new star formation within the local molecular clouds.

And this is what those little dots of light in your 60mm glass are all about! Awesome. But there’s more.

As I said, the Dickerson statement about the nebula being a vacuum still leaves me a bit confused. It is obviously denser near new stars, else the stars couldn’t form. The question is, how dense does it get and how close to those stars do you have to be  to experience clouds?  More to the point, how dense is matter in the area we actually see in our scopes as nebula? I’m just not sure from what I’ve read. But it is something to think about and while thinking about it, why not sit back and enjoy the Trapezium, the nebula, and starbirth in this wonderful animation.

About this animation

From the Hubble Web site:

This animation reveals the topography and beauty of the Orion Nebula like never before. Based on data obtained by the Hubble Space Telescope, all of the gas clouds, stars and proplyds are positioned as accurately as possible. The animation ends with a close-up examination of the proplyd HST-10, where astronomers see dust grains clumping in the early formation of rocky planets, but whose gaseous envelope is also being burned away by the Trapezium stars in the nebula’s center.

Credit: Greg Bacon (STScI), model based on data by C.R. O’Dell (Vanderbilt University), and The American Museum of Natural History/Rose Center for Earth and Space

DSC-60 Plus – Slithering through the lair of the lizard where he hoards a diamond in the rough

Here's the Lizard as displayed by Starry Nights Pro - I like him better than the Hevelius lizard! (Yeah, I added the background color - wanted to see if he would change like a chameleon, but my magic wand seems broken 😉

My first excursion into the realm of the lizard I used Sissy Haas as my guide and once I had found the constellation, quickly checked out 8 Lacerae – very nice silver and pale blue – and 10 and 12 Lacertae, a bit more challenging and less impressive than 8.  But it wasn’t until days later that I did some more checking and learned that several of the stars I thought were just  line-of-sight companions to 8, really were part of it. In short, 8 turned out to be a very special find in a relatively obscure section of sky that’s easier to reach than you may think.

A few nights later with a gloomy forecast I still didn’t have a pursuit plan mapped out, however, and I went to bed real early figuring on reading when I got up in a few hours. (No I don’t sleep very long.) I was dead tired, having, among other things, evicted mice from my unused  small observatory and cleaned up after them. (An operation had kept me out of the observatory for  three months because I couldn’t lift the shutter or rotate the dome. Now, my strength recovered, I was ready to get back to using it.)

When I glanced out after a few hours sleep I was surprised to see Jupiter burning a hole in the haze to the east. Great – I  needed to at least align the finder on the TV 101, so I would do that and maybe look at Jupiter a while. But instead I lined up the finder on Vega, got a really nice split of the double double (very steady skies) and then went searching for – and quickly found – Comet Garradd which had just recently paid a visit to the Coathanger.  Hey – this was a much better night than the weather folks had predicted! Don’t you love it when that happens?  So now I went for  8 Lacertae with the idea of finding all its components – and did so quickly with the 101. Then I noticed the 60/1000 Tasco sitting there on a shelf feeling ignored. I quickly swapped the 101 for the Tasco and enjoyed myself for better than two hours until the clouds closed in just as I was closing in on M34.

Lacerta may be totally unknown to you – as it was to me – but this is a three-for one sale – find one multiple star in Lacerta  and you get the two others free of any extra effort.

In fact, the one is a  Sissy Haas  “showcase” and  Double Star Club double – that is both lists treat it as a double and that’s how we’ll treat it at first – but it’s really a quintuple that even in a 60mm scope makes a stunning triple. And nearby are two other doubles, 10 Lacertae and 12 Lacertae.

But enough! Let’s start with 8 Lacertae and how to find it, because I have to admit this is a general area of sky I’ve managed to pretty much ignore over the past half century or so. I’m lazy and where there aren’t bright guidepost stars I seldom venture. But I was feeling adventuresome on this night and besides, I wanted to find something John hadn’t gobbled up yet – something good. So I turned to the Lacerta section of the Haas book, and there were 8, 10 and 12 Lacerta, with 8 getting the coveted “showcase pair” designation. That was enough for me – lead me to the lizard! (Yeah, Lacerta is Latin for “lizard.” This isn’t one of those classic constellation, this is one that modern dude  Johannes Hevelius dreamed up when he was creating his own sky charts in the late 1600s.)

The trick, however is to find the lizard. So first you have to know the general area of sky to search. Here’s a chart  that shows how Lacerta is bounded by better known – and brighter constellations.  Though Cepheus is hardly bright – Cassiopeia, Andromeda, Pegasus (Great Square), and Cygnus are.  If you are familiar with Cepheus you can draw a line from Zeta Cephei to Eta Pegasi and you’ll find the “Little Cassiopeia” W on that line – and continuing south you’ll find 8 Lacertae.

Finding Lacerta - click image for larger version of this chart. (Prepared from Starry Nights Pro screen shot.)

Starry Nights Pro does a connect-the-dots routine for Lacerta that looks like this – sort of a lightning bolt.

That may look easy enough to find once you know the general area of sky to look in – but nearly all those stars are either at the weak end of magnitude four, or the strong end of magnitude five. So – if your eyes are well dark adapted and your skies dark enough so you can see all seven stars in the Little Dipper, you should be able to detect these  with your naked  eye.  While I can just do that in my skies, I still found it confusing, so I took an easier route. I used low power binoculars with a 7-degree field. Here’s what that gives me when looking at just the northern portion  –  essentially a little version of Cassiopeia’s well-known “W” asterism.

If you are comfortable you’ve found Lacerta, then finding 8 Lacertae should be easy with either binoculars or finder. You get “Little Cass” in your field and move south about one field of view. Here’s what you should see. That little diamond is a bit irregular – a diamond in the rough – but I find it shows up well in small binoculars or finder and is my key for locating not only 8, but 10 and 12 Lacertae as well.

Click image for larger view. (Prepared from Starry Nights Pro screen shot.)

But the one you want to start with is 8 Lacertae because it is so easy to split, even with a 60mm scope, and once you’ve found it, it will be much easier to identify the others. What’s more, while 8 Lacertae is a wonderful double in any scope – a real gem – it is a very nice triple in a 60mm and in a 100 mm or larger it becomes a quintuple. In fact, if you are careful about your identification, you’ll see a quadruple with a 60mm. The problem is that last star is far out and easily confused with other stars in the same field.

For me this also proved to be a reintroduction to the  sharpness of a Tasco 60mm F16.6.  What a lovely scope for doubles! And mounted on a T-Mount (a short, sturdy parallelogram mount made by Universal Astronomics) it was absurdly comfortable to use even though 8 Lacertae was very near the zenith at the time of observing. And truth is, the diamond I speak of was best revealed in the 6X30 finder on that scope. (A larger finder showed more stars and that tended to obscure the pattern.)

For the Double Star Club all you need to find is 8 and split it as double. Here’s the Club’s listing.

8 Lacerta

22h 35m.9

+39° 38′

5.7, 6.5

22.4″

186°

But even if you’re using a 60mm, don’t cheat yourself by not looking for more.  Just take your time, pay real close attention to position angle, split, and magnitude of the various components.

8 Lacertae

RA: 22h 36m Dec: +39°38′

Mag: AB 5.7, 6.5; AC 5.7, 10.5; AD 5.7, 9.4; AE 5.7, 7.2

Sep: AB 22.2″; AC 48.6″; AD 81.7″; AE 336.6″

PA: AB 185°; AC 158°; AD 81.7°; AE 239°

Spectral type: A – B2Ve , B – B2V, C – ?. D – A0, E – F0

Whew! That’s a lot of  numbers, but take them one at a time.  First, the AB split is wide  and there’s less than a magnitude difference, so this is simple, Just sit back and enjoy – but also note that the PA  is 185° and since that’s nearly due South it gives you a good idea as to the direction of the remaining, more difficult stars.

AD was easy for me to spot next for two reasons – first, the separation is almost four times that of the AB pair, and second it’s a full magnitude brighter than the C component. And if you take AB as an indicator of south, than AD is roughly east at PA 81.7°.

Those three then fit together to make a reasonably compact triple when viewed at 90X in the 60mm. But with the 60mm I really couldn’t find the C component. It was too close to the brighter stars and at magnitude 10.5 is the dimmest of the group. The separation and PA tell you it’s roughly halfway between B and D in the south southeast area.  I already had a pretty good idea where it was because I had seen it reasonably easily with the 4-inch. But honestly, I wasn’t sure I was detecting it with the 60mm, though I got a hint of it from time to time.

The E component is difficult only because it’s so far off and can be confused with other stars in the field that are apparently not members of 8 Lacertae.  Once again, though,the numbers come to your rescue. First, the PA is 239° – that’s darned close to southwest and since AB indicates south you should have an easy time knowing which direction to look.  What’s more, at 7.2 E is quite bright and it’s a whopping four times as far away as D.

That still means it should be well within your field of view. For example, if I were using a 10mm Plossl (100X) on my 60mm Tasco, I’d have a 30 minute field of view. Put AB in the center of that field and E would be about 6 minutes away – a bit less than half the distance to the edge of my field of view. So I would be looking for a fairly bright companion (7.2)  to the southwest of the primary, and a bit less than halfway to the edge  of the field. (Of course your field of view will vary with the scope and eyepiece, but you get the idea. )

Aesthetically E doesn’t do much for me – but it’s nice to have to round out the picture.

Moving on to 10 and 12

To find, review the chart showing the diamond – 10 and 12 are identified on it, as well as 8. I’ll repeat the chart here.

What about 10 and 12 Lacertae? Frankly, they don’t excite me all that much, but I like the fact that they occupy a couple of the other points on the diamond and heck, if 8 Lacertae has brought you to the neighborhood, go ahead and split them!

For me these were targets already found on my first night using the CR-6 refractor. I didn’t feel inclined to pursue them with the 60mm, though I probably will another night. Though their companions are 10th magnitude, the separation is very wide – about twice that of the familiar blue and gold Albireo.

10 Lacertae

RA: 22h 39m Dec: +39°03′

Mag: 4.8, 10.3

Sep: 62.2″

PA: 49°

Spectral type: O9V

I found the primary white, the secondary a faint blue dot nearby. Yesm judging by it’s spectrum you should see some blue in the primary. I didn’t.

12 Lacertae

RA: 22h 41.5m Dec: +40°14′

Mag: 5.2, 10.8

Sep: 69.1″

PA: 15°

Spectral type: B2III

This pair is about half a magnitude fainter than 10 Lacertae, but the PA puts the secondary in the same quadrant and it’s about the same distance, so if you can split 10, you should be able to split 12 – unless, of course, 10 was right on the edge of what you could do.

DSC-60: Three wide doubles in Lyra to get you started – Zeta (ζ), Beta (β), and SHJ 282AC

Splitting Tools for Zeta (ζ) Lyra: Zeta yields to a 15X70 binocular hand held, or 8X40 binoculat mounted; 50mm scope splits it easily.

Finding and splitting these three  wide pairs on a Summer or Fall evening should be a great way to get started with doubles – and if you’re already a veteran, they’re still worth a look. Veterans may find it more challenging to give them a try with binoculars – or that little, old 50mm refractor you bought on a whim!

Naming them is a bit more difficult for SHJ 282AC is listed in the Double Star Club (and elsewhere) as OΣ 525 and may be identified on your star charts simply as HIP92833. The Cambridge Double Star Atlas lists it both ways – OΣ 525/ SH 282.  But this naming thing is a footnote – let’s get to the meat of the matter, how to find them.

First, these three are easy to find. All you have to do is locate one of the brightest stars in the sky – Vega. Then work from there. (Vega is the second brightest star in the northern hemisphere and about as close to magnitude zero as you can get. In Suummer and Fall it’s high overhead in the evening for northern hemisphere observers.)

As with most constellations, I have difficulty making a lyre out of the stars of Lyra, but I have no problem seeing two linked asterisms –  a triangle and distinctive parallelogram.

The Lyra triangle and parallelogram asterisms. This whole chart can fit in the field of many low-powered binoculars and the Vega triangle fits easily in a finder or very low power telescope field. Since the magnitude of key stars range from 3 to 6, you may need binoculars to see these asterisms in a light-polluted area, though you should be able to see Vega anywhere with the naked eye.

I always find my way about Lyra in two steps. First I find Vega and the two stars that form a triangle with it. The northern most of these stars is the famous Double-Double. The other is our first target tonight, Zeta (ζ) Lyrae. 

Zeta forms a bridge then to the rest of Lyra which is nicely marked by a parallelogram. Zeta marks the northwest corner and Beta (β) Lyrae (Sheliak), the southwest corner of this parallelogram. I always use Beta as a guide to finding the wonderful little Ring Nebula, M57. It’s about three-quarters of a degree to the east. If you’re familiar with it, you can use it as one corner of a triangle that consist of Beta, M57 and SHJ 282AC. If you don’t know  – or can’t spot – M57, just go straight to SHJ 282AC. It’s little more than a degree northeast of Beta and at sixth magnitude considerably brighter than M57. (Hmmm…the shoe fits better on the other foot!  If you’re looking for M57 then SHJ 282AC might actually be a help in finding it!)

These stars are all remarkably similar in the distance between them – about three quarters of a minute of arc. And Zeta and Beta are almost identical in position angle – so you can use Zeta to tell you where to look for the secondary to Beta and that should be a help since there’s five magnitudes difference in the Beta pair making the 8.6 magnitude secondary a little more difficult to spot in a small scope.

I, of course, used the 60mm Televue, my standard for the DSC-60 project. (For project details go here.)

John has already posted an excellent report on Zeta and Beta and you’ll find his write up here, so I won’t repeat all the details.

Zeta (ζ) Lyrae 

Stats from the Double Star Club List:

Zeta Lyrae

18h 44m.8

+37° 36′

4.3, 5.9

44″

150

Haas lists the secondary a little brighter – 5.6. This pair is about 154 light years from us and has spectral classifications A, F0.

I found this split nicely using a 24mm Panoptic – 15X.  I actually  started with a 24 – 8 zoom, but really didn’t like the views I was getting. The 13mm Nagler gives a really solid feel at 28X and it was fun to crank it up a bit with a 5 mm Nagler – 72X. With that last I saw the colors of this pair as silver and violet. Lots of stars share the field of view, even at 72X, but none crowd it.

Don’t take my color report too seriously, however – people seem to be all over the map on the color of these stars. Haas reports a paid of “goldish white” stars and says Smyth saw them as “topaz, greenish,” while Webb saw “greenish white, and yellow.”  John saw them as yellow and white in a 60mm – but saw both having a yellow tint when he switched to a 6-inch.  Oh boy! Time to move on to Beta.

Here’s the DSC listing for Beta.

Beta Lyrae

18h 50m.1

+33° 22′

3.4, 8.6

46″

149°

And here’s John’s summary of facts:

Beta (β) Lyrae (Sheliak)

RA: 18h 50.1m   Dec: +33°  22′
Mag:  AB – 3.6, 6.7  AE: 3.6, 9.9  AF: 3.6, 9.9
Sep:  AB –  46″          AE:  67″        AF: 85″
PA:    AB – 150°       AE: 317°       AF:  19°
Distance: 881.5 Light Years
Spectral Classification for A & B: B7, A8

Notice that John includes  a couple of other components. You don’t need to see these for the DSC, just the A-B components. But please note the large difference in reported magnitude between the DSC list and John’s numbers.  John list these stars as 3.6 and 6.7 – which are the magnitudes found in Haas and in the Washington Double Star Catalog.  I trust John’s sources and I can’t explain why the DSC list appears to be off – but I suggest you simply take it as a warning that the DSC numbers may not only be dated, but have some other errors in them. I include them because this is the official list for the Double Star Club certificate.

When I get looking for Beta in the scope I find it easy to confuse with the other southern corner star until I remember that one of these stars has several other bright stars in the field – and Beta is pretty much alone. I found the five magnitude range between primary and secondary made this a challenge at 15X, but a downright elegant sight at 28X. I saw the primary as white and – maybe this is a blessing – I could make out no color in the faint secondary. Haas has it as “sapphire” and Smyth – bless his colorful eyes – saw it as “pale grey.” Guess I could go with either of those descriptions, especially if I were using a larger scope  – but in the 60mm I just am not ready to say.

Now color is the hallmark of our third easy double – in fact, Webb describes it as a “beautiful miniature” of Albireo – Beta Cygni. That comparison didn’t jump out at me, but I did see a pale orange primary and blue secondary.

The other hallmark here is the name. The DSC list identifies this as “Otto Struve 525.”  Not really. OΣ 525 is the primary and the “B” component and thankfully the DSC is not asking you to split that – especially with a 60mm. That pair is 6.1 and 9.1 and just 1.8″ of arc apart!  But look at the magnitudes in the DSC listing, as well as the generous separation of 45″ and it seems obvious they are talking about another pair – a pair both Haas and the Washington Double Star Catalog identify as  SHJ 282AC.

Now honestly, I don’t understand enough about the nomenclature to know what’s most proper in this case. Seems to me it should be SHJ 282AC which gives the credit for this star to South, J. and Herschel, J. But OΣ 525 does refer to the same primary and Starry Nights Pro simply list it as HIP92833.

So if you’re going  for the DSC certificate, you’re looking at OΣ 525, but that really means the easier of two pairs – technically the AC pair.

Otto Struve 525

18h 54m.9

+33° 58′

6.0, 7.7

45″

350°

This combination is a whopping 1,339 light years from us and the primary has a spectral classification of G8III. Notice that spectrum puts it on the orange side of yellow, so that fits my vision of a “pale orange primary” and also fits the comparison to  Albireo where I always think of the primary as “gold.”

Can’t wait to give these three a shot with mounted 15X70 binoculars.

DSC-60: Delta Herculis – will-o’-the-wisp

This is a DSC-60 Project observation –  for project details go here.

Stats from the Double Star Club List:

Delta Herculis

17h 15m.0

+24° 50′

3.1, 8.2

8.9″

236°

For a finder charts and a look at how Delta Hercules fares with other scopes read John’s post on it here, as well as the comments on that post.

The Double Star Club listing  treats this as a double only and the listing appears out of date. Again, John’s post deal with all four stars and gives more recent stats for the B component which show a separation of 12.4 seconds and a PA of 286°.  Given those numbers – in fact, given the earlier numbers even, you might expect this to be easy. It isn’t.  The C and D components are easy, even though they’re a couple magnitudes fainter, because they are each roughly three minutes from the primary.

Locating that B component – the object you need for the Double Star Club, is much more difficult.  With the 60mm and my  5.5 skies it was a will-o’-the-wisp. I saw it – but I suspect I saw it only because I had seen it a few nights before  using an 85mm and 102mm, so  I knew exactly where to find it. And with the little TV60 it definitely required averted vision and good dark adaption. I used a 4-2mm zoom and I could see it at the 4mm setting (90X), but only with averted vision. It pops in and out – more often out of view than in view.

So I would count this one as seen – barely – and also as a lesson in how difficult it is to see even a magnitude 8 star when it has a companion just 12 seconds away that is five magnitudes brighter. Much the same challenge you have with Polaris where the difference is greater, but so is the separation.

DSC-60: Iota Cancri – in search of the real Winter Albireo!

This is a DSC-60 Project observation – for project details go here.

]

Iota Cancri

08h 46m.7

+28° 46′

4.2, 6.6

30″

307°

I was looking for what I thought was the “Winter Albireo” – Iota Cancri, which is in my eyes a good imposter  of Albireo. I enjoyed it immensely – beautiful double, but the real fun started when I got back in the house, sat down with my notes and discovered I had not been looking at what others call the “Winter Albireo” at all. What’s more, I think I can make a case for my candidate – Iota Cancri, over the more popular one, h3945. But first, the background.

Iota is fascinating in its own right and quite easy to find on a spring evening since its one of the brighter stars in the dim region between Leo and Gemlni  that we know as Cancer the Crab.  If you can find the Beehive (M44) , a large and beautiful open star cluster, then Iota is the 4th magnitude star nearly due north about one fist -held at arms length – from M44..

Your fist held at arms length covers about 10 degrees – just a bit more than the distance between the Beehive and Iota Cancri. (Prepared from Starry Night Pro screenshot.)

This is one of the doubles featured by Guy Consolmagno and Dan Davis in their beautiful observing guide, “Turn Left at Orion.” The primary is a giant and while the two stars are gravitationally linked, they are quite far apart as doubles go. (Almost as far apart as the real Albireo and a bit farther apart than what others call the “Winter Albireo.”)  Consolmagno and Davis note that if you were on a planet that orbited the primary star, you”would see its companion as a very bright star, about half as bright as the Full Moon. ” From a planet orbiting the secondary, the primary “would look about four times brighter than the Full Moon.” I love to carry images like that in my head to the telescope and ponder them as I observe.

But I’m getting side tracked.  See, Iota Cancri looks so much like Albireo to me that I have written “Winter Albireo” in the margins of two of my observing books next to the Iota Cancri entry.  When I saw those notes as I was planning this observing session, I assumed that was it’s accepted nickname – wrong!  Seems like the only one calling Iota Cancri that is me. Or at least I can’t find any other reference to it as such.   What I did find, as I said, is that another double I’ve never seen is called the “Winter Albireo” by many  others and is generally regarded as too frequently neglected. Well, mark me down as “neglectful” – I’ve never seen Herschel 3945, but now I am really curious, so it has moved to the top of my “to be observed list!” And when I do observe it I may change my tune, but from what I’m reading I just don’t see how they give it this nickname while ignoring Iota Cancri.

I love Albireo. Nothing can replace it. My observations of it go back nearly half a century and I’ve never tired of looking at it. I always see it as gold and blue – very easy to split and with dramatic contrast.

And when I looked at  Iota Cancri  on this occasion I saw a wonderful yellow – pale yellow – primary and a beautiful, deep, sky-blue secondary. So I will readily admit that my idea of the “Winter Albireo” doesn’t quite measure up to the summer one, but it comes close.  I confirmed this by getting a couple hours sleep, then getting up and observing the real Albireo while the memory of Iota Cancri was still fresh.

So when I got in to write this report I decided to check on the spectral types to see if that gave me a solid guide to these color differences.  Guess what? It does – but it opens more questions.  The Albireo primary is a K3, the Iota Cancri primary is G7.5.  Look at the chart in the Star Colors post and you’ll see that  we tend to perceive G stars like Iota Cancri as “yellowish white.” Whereas K stars, like the primary of Albireo, tend more towards the orange.  So “pale yellow” for Iota and “gold” for Albireo seem to fit. The secondary’s also match the spectral classes. The Albireo secondary is B8 and the Iota Cancri secondary, A3 – that makes the Albireo secondary a somewhat richer blue, but they both tend towards blue.

Yes, this is splitting hairs because colors are so difficult to perceive, but having observed them within a matter of hours of one another, I did come away with just that impression – Iota Cancri makes a credible imitation of Albireo, but in the end Iota is just not as intense.

And what about the star so many do label the “Winter Albireo?” There my curiosity is really sparked.  The h3945 primary is a K0 – so that pushes it over closer to the yellowish-orange of the real Albireo primary. So far so good.  What throws me, though, is the spectrum of the secondary. It is listed as F0! That puts it in the white category in terms of our perception – or certainly a very,very pale blue. Not nearly so blue as the B8 of Albireo, or the A3 of the Iota Cancri secondary.  These deductions based on spectral class also match the description in “Turn Left at Orion.”

Herschel 3945 gets attention under the “Also in the neighborhood” category of “Turn Left at Orion” – just not the neighborhood of Iota Cancri.  They link it with observing an open cluster, NGC2362, in Canis Major.  They note that the primary is a “distinct red, while it’s companion may appear white or yellow.” Huh?! Does that sound like Albireo to you? Red and white/yellow?  What happened to gold and blue? I find their description in tune with the spectral classification, but out of tune with Albireo.  Still, they note that this double  is more popularly known as ‘The Winter Albireo.’  Indeed the color contrast and separation are reminiscent of Albireo…” Oh boy! Color contrast maybe, but not color. Now I really have to get a look at these stars!

So I’ll report back here after I’ve looked at h3945 and we’d love to hear from others on how they see these three stars. Here are the vital statistics for each.

Beta Cygni

19h 30m.7

+27° 58′

3.1, 5.1

34.4″

54°

K3, B8

Iota Cancri

08h 46m.7

+28° 46′

4.2, 6.6

30″

307°

G7.5, A3

h3945 (Canis Major)

07h 16m.6

-23° 19′

5, 5.8

26.8“

52°

K0,F0

Just looking at the stats, they do all look pretty similar until you get to spectral class and in that  I would think Iota Cancri would be a  better match.

And h3945? How does Sissy Haas see it? Well, she reports the stars “are bright citrus orange and royal blue: the colors are seen vividly and in strong contrast.”

And, of course, we have discussed many times  the variables involved in seeing color differences – but there may be something special here in h3945. I can’t wait to see for myself.

Update: March 12, 2011

Conditions certainly could have been better, but seeing was just a bit below average and I found a hole through the bare tree branches where I had a clean shot at h3935 and guess what? It’s every bit as  beautiful as folks say – but in my book it is not the “Winter Albireo.” In fact, the colors remind me more of Rasalgethi  (Alpha [α] Herculi) – orange going to red with a blue companion. I think one thing that separates it from Albireo, besid the colors, is the primary just isn’t as dazzling. With Albireo you’re seeing  a magnitude 3.1 primary, whereas  h3945 is nearly two magnitudes fainter.

I would also say that I’m looking through a lot of atmosphere – I caught it when it was about 24 degrees above my southern horizon which is only a couple degrees lower than it is at transit, so I can’t do much better. I suspect that contributes to the redness  however. Folks in the southern states  have a better shot at this beauty. I used the Televue 60 with a 10mm Tak for 36X which to my taste gave very nice proportions.  It was just as attractive in the TV85 with a 13mm Nagler – 46X.

Want to take a look for yourself? Here’s a finder for the “Winter Albireo” aka. h3945.

Look for the triagle of bright stars south of Sirius. Atsra with Adhara and go to Wessen – consider that one step. Continue moving inthe same direction the smae amount (about 3.5° – and you willfind yourself at h3945.

Now that said, the overall impression of the true ALbireo in a 60mm scope at 72X left me duly dazzled  – and smiling broardly at the winter imposter. Oh Iota Cancri is nice. It is wonderful, really – it just isn’t Albireo. But it’s a darned good substitute on an early Spring evening.  Hmmmm. . . and maybe that’s the solution. When I made this observation it was still winter and Iota was well placed at a reasonable hour.  So i guess that makes it a winter star. But I have to admit, it feels more like a spring star. So maybe I should give the Big Dog his “Winter Albireo” regardless – and give the Crab a Spring Albireo!

DSC-60: Sigma Orionis – an easy triple that would get more attention if it wasn’t in such a great neighborhood!

This is a DSC-60 Project observation – for project details go here.

Sigma Orionis

05h 38m.7

-02° 36′

4.0, 7.5, 6.5

12.9″,43″

84°, 61°

Sometimes it doesn’t pay to be in such a good neighborhood – it’s too easy for folks to ignore you. even when, like Sigma Orionis, you’re a beautiful and easy triple. Well, a quadruple really, but the DSC list it as a triple and the fourth star can be difficult to dig out.  OK, it’s actually five stars, but the last one is next to impossible, so I don’t count it – but it’s why you see the primary referred to sometimes as “AB” rather than just “A.”  Sigma is just an easy hop away from the dazzling Trapezium, a quadruple that is so good – and so in reach of everyone – that I hardly think of the Trapezium as a multiple star. It seems to be in a class by itself.

But if you like the Trapezium, take a little trip up to the eastern end of Orion’s belt. The bright star is Alnitak, but a bit less than a degree to the southwest (PA 218) of it is Sigma. The two can fit in a low power eyepiece. John includes some nice charts and some other neighborhood highlights in his post here. You will be delighted with Sigma as an easy triple. You will be challenged, but pleased to see you can turn it into a quadruple.  And as I said,  don’t even think about that fifth star – there’s only a quarter of a second separation between it and the primary.  And while we’re on the subject there are really a couple more stars that go with the Trapezium, but they too are difficult – though not impossible – targets.

Meanwhile, Sigma is just fine as an easy triple – the three main stars are bright and the separations wide. I come to this star often, but my first try with the 60/360 was on the first night out with that small scope, February 14, 2011. Using a 7mm Nagler (51X)  I had a solid split of the three components listed in the Double Star Club – absolutely charming. The primary is a whitish blue, the star closest to it is a steely blue and the third star I see as yellowish. I could not see the fourth star, even though I know right where to look for it. I did see it easily a couple weeks later when using an 8-inch SCT and it can be dug out with smaller scopes.

But what strikes me here goes to the heart of why multiple stars are so much fun – they are so different from one another! Look at Sigma, then look at the Trapezium, and while you’re in the neighborhood, swing over to Beta Moncerotis. Three multiple stars giving you three distinctive looks – all different in the pattern they form with one another, in their colors, and in their different magnitudes and separations.!

DSC-60: Beta Monocerotis – a primary with twins!

This is a DSC-60 Project observation –  for project details go here.

Beta Monocerotis

06h 28m.8

-07° 02′

4.7, 5.2

7.3″

132°

Hmmm… now that’s curious. The Double Star Club list has this as a double, as you can see from the above data taken from that list. The data is accurate as far as it goes, but the real charm of Beta  Monocerotis – aside from letting those words roll off your tongue – is it’s a delightful triple.  It’s like a primary with identical twins! That 5.2 secondary is a 5 and 5.3 star, as John notes in his summary table and his post found here.

Magnitude              A: 4.6            B: 5.0        C: 5.3
Separation            AB: 7.1″         BC: 2.9″
Position Angle     AB: 133°        BC: 108°

Splitting the secondary is a bit of a challenge, but the little 60/360 handled it just fine and there certainly are more difficult stars in the DSC list.  Monoceros is hardly the best known of constellations, so if you don’t know how to find this,  see John’s post which has plenty of charts. While it’s a rather empty section of sky, it’s sandwiched between Orion and his two dogs, so tracking it down isn’t all that difficult and it’s well worth the effort.

I made this observation March 1, 2011 – I think it was my first chance to use the Nagler 4-2 zoom on the Televue 60 scope – love that combination. Just perfect for star-splitting.  It’s really fun to center a close double, then watch it go from squashed, to a figure eight, to kissing, to a hairline split, and then a solid split as you turn the dial and move down the click stops.  The squashed was the 4mm setting, the figure eight 3.5, kissing, 3, a hairline split at 2.5 and a solid split at 2.

Those half stops may sound like small changes, but they’re significant. On the 60/360 scope they represent a slide from 90X, to 103X, to 120X, to 144X, to 180X – and that last is really pushing it for a 60mm scope, but conditions were very nice.  (Notice how I worked in our agreed upon terms for defining splits? That’s because we just posted them – with a neat graphic – in the FAQ. Take a look. It’s on the green tab at the top of the page.)

Again, my experience was a little different, color-wise, from John’s. I saw just a hint of yellow in the primary and  a very definite light tint of blue in the other pair – the blue certainly is supported by the B3 classification for all three components – but,of course, that doesn’t explain the yellow tint I saw in the primary. In fact these stars should all show the same color and John reported them that way, though he saw them as white which may have had something to do with the bright moonlight during his observation.  I like it better when our reports agree with the spectral classifications, but what you see is what you see. Just too many variables in this color business, as John explains in another one of those green tabs at the top of the page – “Star Colors.”

DSC-60: Epsilon Bootis – Izar, a pair of delicious fruits

This is a DSC-60 Project observation –  for project details go here.

Epsilon Bootis

14h 45m.0

+27° 04′

2.5, 4.9

2.8″

339°

Maybe it’s because it’s 4 am and I’m getting hungry, but all I could think of when I saw this solid split of Izar was an orange with a little blue grape beside it – beautiful.

And  here we go with color perception again. John, in his more detailed report (with charts ) on Izar here, says this about the colors:

. . . Haas describes the primary as amber-yellow and the secondary as deep blue.  She credits Smyth with “pale orange; sea green,” which pretty well describes the colors I see, although I lean more toward gold than green in the secondary – but I can clearly see the green tint most of the time.

Go figure! We have an “amber yellow” and two votes for “pale orange.” Not me. It was deep orange – like fresh-off-the-tree orange. In fact, more like the color of the orange that you see when you bite into it.  But that’s OK. With the secondary I’m with Haas with a definite blue. But Smyth has it “sea green?” OK, that’s close to blue – and John sees the green tint but leans more towards gold? I don’t question any of these observations, of course, but it just never fails to amaze me how the same two stars can result in such varied reports.

I was using a 2.5mm eyepieces on the 60/360 – 144X. This was March 2, 2011 and it was one of the best splits I can remember of this double, an old friend.

DSC-60: Beta Orionis – Rigel, the brighter giant

This is a DSC-60 Project observation for project details go here.

Beta Orionis

05h 14m.5

-08° 12′

0.1, 6.8

9.5″

202

Maybe I should call my new little scope Jack – as in Jack, the Giant Tamer. No bean stalks here, but on it’s first night out I turned it on the difficult double Rigel on a whim and to my surprise, it brought the blue giant to heel immediately. There, shining steadily while stellar flames darted all around it, was the 7th magnitude companion!

Wow! I was impressed. OK, it’s a Televue 60, so it no doubt has good genes and it had just done a fine job on some other doubles, but Rigel is no piece of cake for any telescope. The 9.5 second separation between primary and secondary certainly is generous enough for any scope, but the nearly seven magnitudes in difference between primary and secondary makes that separation seem much smaller than it is. In fact, I remember reading a few years back that Rigel was a great warm-up star for those wishing to tackle Sirius whose “pup” has been notoriously difficult to see in recent years, but the separation is widening making it easier.

Then I reviewed the  table in the introduction to the Sissy Haas book. Oops. The “pop” you heard was my bubble bursting.  By the numbers, Rigel shouldn’t be all that difficult.

In the table I’m talking about  she shows that a 60mm should be able to handle a 2″ separation – if the stars are the same magnitude.   She then builds that table up to include a four magnitude difference where she says the split, if it is to be detected by a 60mm scope, should be at least 4.5″ – and there she stops.  I haven’t been able to deconstruct a formula from the table, but the trend is pretty obvious – and it says I shouldn’t be so shocked because with 9.5″ separation even a 60mm should find it reasonably easy to split two stars despite a seven magnitude difference between them.

Nevertheless, I still think I’ll call it Jack in honor of a no hassle split of Rigel, because more than one night I have found this star difficult with much larger scopes, though, of course, seeing plays a major role.  The seeing on this night was good – probably a four out of five where five is the best.  I should add it was good only for about an hour, then everything deteriorated quickly – transparency and seeing. Got colder, too – though it was already darned cold in what has been one of the most wintry winters in memory.

But the heck with the cold, let’s get to the hot stuff – the real hot stuff – Rigel. Do I need to tell you how to find it? It’s the blue/white star int he foot of Orion – his western-most foot

 

Orion and friends as Stellarium represents them with, I think, a little whimsy. I mean, should Orion be more concerned about Taurus charging down on him? Or Monoceros - the Unicorn - who has a gleam in his eye and a mean look on his lips and a single sharp horn aimed at the hunter's backside! (Oh- note Rigel - and yes, if you click this image you'll get a larger version. And check out our "resources" link at the top of the page for more information on Stellarium.)

 

 

Like nearby Pollux, it looks like Rigel was short-changed having been designated the “Beta” star of the constellation Orion while dimmer Betelgeuse is the Alpha. Of course, Betelgeuse, being variable, may have been brighter when Johann Bayer made his designations in 1603. Bayer’s “system” is inconsistent, however, to say the least, so there’s no sense getting too worried about this.

Like Betelgeuse, Rigel is a supergiant. It’s huge and it’s brilliant too – and since it is more distant (860 light years), it is intrinsically more brilliant than Betelgeuse. Jim Kaler writes: “Only about 10 million years old, Rigel should eventually expand to become a red supergiant very much like Betelgeuse is today, by which time it will be fusing helium into carbon and beyond in preparation for its eventual explosion as a supernova.”

Rigel’s radius is 74 times that of the Sun, 0.34 Astronomical Units, nearly as big as the orbit of Mercury. Words don’t do that justice. I came up with this little graphic to show how large Rigel is in comparison to nearby Adebaran.

Get the picture? Our Sun, large enough to hold one million Earth’s, deserves the appelation “dwarf” when you compare it to Rigel and Aldebran,  Before you look through your telescope at Rigel, pause. Take a look with the naked eye. Imagine Rigel expanding to cover all of the stick figure of Orion – and that’s only half of it! Of course we’ll leave Betlegeuse out of it. In fact, I had to leave Betelgeuse out of the graphic because it’s just too darned big to fit into it. Where Rigel would reach past the planetMercry were it taking the place of our Sun, we would be inside Betelgeuse  and it would cover everything else almost out as far as Saturn!

I guess in that sense it deserves to be called Alpha. But Rigel, with its brilliant blue light, will always hold my imagination in part because i can imagine it,  And now it also stands as one of Jack’s first conquest and one the first of the Double Star Club 60 mm  observations. Betelgeuse, after all, is only a single, right? And sure, it might go super nova in 2012 and that has the internet rumor mill going crazy already – but that sort of ignores the fact that while that prediction has some scientific validity, it would also be scientifically accurate to say it might go super nova a million years from now 😉 Rigel, thankfully, is caught up in no such rumor mill yet.

Vital stats:

• Brilliance: Magnitude 0.12, the 7th brightest star in our sky. Shines with the luminosity of about 90,000 Suns.
• Distance: 860 light years
• Spectral Type: B
• Position: 05h:55m:10s, +7°:24′:25″