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Fire in my Fingers: 44 Boötis and its Shadow, OΣ 291

About the middle of this past April, a message from Neil English landed in my inbox, asking if I had looked at 44 Boötis, followed by a description that caused my focuser fingers to start twitching and itching.  He had resolved its 1.4” separation at 225x in his five inch Russian Tal 125 refractor, Tonya, but left me hanging from the end of my focuser when he wondered out loud if it could be resolved with a four inch refractor.  I didn’t hang there for long, though, because a few days later I received another message from Neil which featured a drumroll, and then a — “no problem!”  Using his Skylight four inch f/15, he netted a pair of crowded airy disks at 250x, and at 300x he found a sliver of black sky running between the two stars.

And of course that did it. Now I had to see it for myself – in my f/13 version of the Skylight 100mm refractor.  And I expected a tough time of it, too, because the skies above me are seldom calm enough to yield up their secrets when I try to penetrate the two arc second separation barrier.

So I proceeded to impatiently wait for the weather to cooperate, and just when I was about to give up until the middle of July, I stuck my head outside and found myself looking at clear midnight skies.  Clear, yes – at least over the upper two-thirds of the sky – but lurking around the fringes of the horizon were the familiar sinister hints of dense obscuring forms that I knew were accumulating energy enough to make a sudden lunge for the zenith.  And as it turned out, they were busy soaking up enough of a surplus to deliver a few totally unexpected surprises.

44 Boötis  (Σ 1909)     HIP: 73695     SAO: 45357
RA: 15h 03.8m   Dec: +47° 39′
Magnitudes: 5.2, 6.1  (B is variable, 5.8 to 6.4)
Separation:  1.4″
Position Angle: 63°  WDS (2012)
Distance: 42 Light Years
Spectral Classification: F7, K4

NOTE: The separation is closing quickly on this pair.  As of Jan 1st, 2017, the WDS shows it narrowing to 0.685″ at 73.8° and in 2018 it narrows further to 0.534″ at 79.0°.  By 2020, it’s down to 0.273″ at 112.0°.

Once I found my way up to my destination, I had a sneaking suspicion I had been here before.  Sure enough, after checking my Boötes files, I found I had wandered as far east as 39 Boötis back in July of last year, but stopped there since it was at the end of an extended tour through the Herdsman’s club.  So I had little problem recognizing the area, but for those who haven’t been here, I’ll be glad to provide some directions:

There are a couple of ways to get here. One is to draw a line from Kappa (κ ) Boötis to 39 Boötis, and extend it about two degrees further to reach 44 Boötis. Another way is to finish the rectangle started by the lines that run from Beta (β) to Gamma (γ) to Lambda (γ). The northeast corner of the completed rectangle will place you just to the west of 44 Boötis and OΣ 291. The first approach is shown on the chart above in yellow and the second in turquoise. (Stellarium screen image with labels added, click for a larger view).

So after overcoming the shock of seeing stars shining in scintillating midnight splendor above me, I set up my four inch refractor and aimed it into the void north of Boötes’ upper diamond-shaped framework.  And I found myself face to face with another pleasant surprise.

I could see 44 Boötis plainly enough, with no aid to my vision other than my glasses.  It was a bit faint through the atmospheric moisture left by the breezes drifting in from the ocean, but still fairly easy to see for one very basic reason – there were three stars clustered together up there, not one — as I soon discovered when I peered into the eyepiece end of the 8×50 finder on my scope (see inset in chart above)

I looked down at the Sky & Telescope’s Pocket Sky Atlas chart I was holding in my hand (it’s chart number 42 if you’re using it) – and sure enough, it showed three stars where I had expected only one.  The one in the middle was my goal, the one to the southwest was the star we’re going to look at shortly, OΣ 291, and the one to the northeast turned out to be 47 Boötis.  That one also happens to be a double, cataloged as Bu 1086, with magnitudes of 5.6 and 13.3, separated by 6.6” – more than a bit beyond my reach, I suspect, because of the wide magnitude difference.

At any rate, all three of those stars, sitting there very calmly in the eyepiece of the finder scope about half a degree apart, made for a rather stunning and unexpected sight.  And it certainly never hurts to get off to a rollicking good start when trying to shake the rust out of a pair of rain saturated eyes.

H 53, an unexpected bonus, is shown here at the upper right — the magnitudes are 8.9 and 10.9, separated by 87.2″ at a PA of 358* (WDS 1999) (East and west reversed, click for a larger view).

But it was time now to get to the serious stuff.  I surveyed the scene at 87x with a 15mm Televue Plössl – which netted me the view shown at the right — and then began reaching for implements of separation.  Now honestly, I wasn’t expecting a whole lot here – as I said, the skies just don’t surrender much around these parts except on rare occasions.   In order to keep attention focused on the object of my obsession, I wanted to stick to small fields of view, so I started with a 9mm UO Ortho, which yielded 144x.  And all I could detect was a single star, jiggling back and forth just enough to defy my efforts to bring it into focus.

UO 9mm Ortho, 144x

I settled for what seemed a reasonable focus compromise since it wouldn’t hold still for a tenth of a second – and then suddenly that vibrating image came to a screeching halt – and bless my darned damp Star Splitter hat if that single star didn’t suddenly become two stars hangin’ onto each other!

Hold on, Hannah, there’s hope up in them thar heavens tonightLet’s try that gleamin’ li’l 7.5mm Celestron Plössl!

7.5mm Celestron Plössl, 173x

We did, and at 173x, the image sprouted into a stunning figure eight!  Muchas gracias, ya li’l orange and black chrome cylinder of dee-light!

Well, now  ———

I had to pause to recover my windage and my unaccountably altered vocabulary  ———-

it was time to double up on the ocular power.

15mm TV Plössl at 2.4x, 208x

Out of the eyepiece box came a 2.4x Dakin Barlow, into it went the 15mm TV Plössl I used earlier for the wide view, and then both of them were placed carefully into the diagonal.  And at 208x, I found myself looking at the barest sliver of a hair split.  YES!

And while my right eye was hypnotically tranced over the eyepiece, I caught a sudden flash of light out the corner of the left one.  What the ………… ?

A fireball?  I looked up from the eyepiece  ———-  nothing.  Just a clear sky, the fog still hovering over the ocean, the ocean still whispering to the shoreline half a mile away — but no smoke, and certainly no fireball trail hanging anywhere in the sky.

Hmmmmm.  Well, since the night was still rollicking its way forward in good form, I swapped a 12.5mm UO Ortho into the Barlow, refocused, and at 250x ————–


Solid!  Black sky!  Between both stars!

And then there was another flash.

I looked up again.  Fireball?  Nope.  Headlights?  Nope.  Not a car in sight, nor one to be heard —- and the sky was still clear, and the ocean was still whispering away in the background …………….

What in the quasi-stellar blue blazes was ……………….. ??????

Then I remembered I had left 44 Boötis bouncing around all by itself in the eyepiece, so I went back to it, stared until I was thoroughly saturated, and as I glanced up again, I saw it – lightning!   And the sky directly overhead was still clear.  As a bell.  I got up, walked around, looked over toward the east, and I could see the clouds and fog beginning to move slowly in my direction.  Another flash, and this time it looked like it was coming from the Coast Range mountains to my east.

Well, so be it.  I’d had about three nights over the past four months when the skies were clear for longer than fifteen minutes, and it was obvious this one wasn’t going to last much longer, either.  Right now the sky above me was clear, so I wasn’t budging, lightning or not – even it if meant fire in my fingers.  And since I didn’t see any angry looking jagged bolts aimed in my direction, I put it out of my mind and went back to the telescope, stared at the miracle in the eyepiece until it started doing double-flips, and then nudged the scope over to OΣ 291.

OΣ 291         HIP:73454    SAO: 45326
RA: 15h 00.6m   Dec: +47° 17′
Magnitudes: 6.3, 9.6
Separation: 35.4″
Position Angle: 156°  (WDS 2009)
Distance: 477 Light Years
Spectral Classification: B9

Lurking in the shadow of 44 Bootis,  OΣ 291 offers a pleasant contrast in magnitude and separation  …………  east & west reversed, click for the full size view.

Now this was a pleasant contrast to 44 Boötis, and the reason was that its wider separation, along with the three magnitude difference between primary and secondary, required a different kind of hard staring into the eyepiece.  My eyes had been fixed on those two tight dancing little globes of orange light for so long, that I had to really look hard at first to pick out the 9.6 magnitude secondary of Otto Struve’s two hundred and ninety-first discovery.  But it was merely a matter of visual accommodation, and once I accomplished it, I was rather delighted with what I saw.  These two stars – 44 Boötis and OΣ 291 — really complement each other well.  By the way, if you have a surplus of telescope aperture, you’ll find a 15.7 magnitude cluster of galaxies, Abell 2018, suspended in the sky almost directly behind OΣ 291.


I was beginning to feel rather exposed, sitting there in the middle of my deck, hunched over a long black telescope tube capable of doing double-duty as a lightning rod — and there were still occasional flashes over in the east that seemed to be moving my way.  So I stood up, turned around to see what the state of affairs was to my southwest, and saw the sky was beginning to turn bright, which could only mean one thing: invasion of the fiendish fog.

When it comes hurtling in from the ocean, it approaches over the dimly lit downtown area in a low dive, and the few lights along the main street are reflected off of it’s damp underbelly, turning the brightness level of the night sky up by several orders of magnitude.  Actually, it’s an amazing thing to see – a pitch black night can suddenly become bright enough to almost cast shadows in less than a minute.

I could see it was also beginning to sweep in from the north and the east – in other words, I was surrounded.  And considering that there were still a few flashes over in the east, I figured the fog was really gently prodding me to pack it in for the night.  Which I did, somewhat reluctantly, but smiling nonetheless, as I thought about that dancing display of circular orange orbs I had been privileged to witness.

Now there are a couple of things about 44 Boötis that are worth circling back to retrieve.

The first is that the 6.1 magnitude secondary is a variable star.  Specifically, it’s a class W UMa variable, fluctuating in brightness from 5.8 to 6.4, with a period of 0.2678159 days – which translates into six hours and twenty-five minutes.  A plot of it’s light curve can be found here. Recent studies have also turned up what appears to be a brown dwarf orbiting the secondary, and rather brief information on that can be found here and here.

The second is the fact that the orbit of the secondary around the primary is closing fast, and by 2021 the separation will be down to 0.23 seconds of arc.  So if you want to see it, you better look quickly!  An excellent graph of its orbit can be found here (scroll halfway down the page), along with a list of the changing separation and position angle by year.  A detailed study of the convergence of the primary and secondary can be found here.

44 Boötis was actually discovered by Sir William Herschel on August 17th, 1781, and cataloged by him as H I 15.  He measured the two stars at 1.5” apart with a PA of 240 degrees, and compared them to Castor in appearance (source).  Sirs John Herschel and James South measured a separation of 2.3” and a PA of 229 degrees in 1821, Wilhelm von Struve measured 2.9” and 234 degrees in 1832, and Admiral William Smyth measured 3.3” and 235 degrees in 1834. He looked at it again in 1842, and found it had widened even further, to 3.7” at 236 degrees.  So before the middle of the 19th century, there was a general awareness that 44 Boötis was, to use the Admiral’s words, “a remarkable and highly interesting star.”  (The Bedford Catalog, p. 334)


While I had been busy feasting my vision on the dual orange splendor of 44 Boötis, the quiet of the night was interrupted several times by the high pitched cry of a few geese as they flew over somewhere above me.  Since they don’t sport identification lights, I had no idea how many were up there, or where exactly they were, despite the flashes of lightning.  But gradually I became aware that the few voices had become those of several flocks, and all of them were moving to the northwest, which took them out over the ocean.  I could picture them turning north once they reached the water, heading for their nesting grounds on the headlands just a few miles from where I sat, something I’ve seen them do hundreds of times in the light of day.

Now there have been more than a few nights when I’ve been serenaded under the stars by a couple of widely separated packs of partying coyotes, but I can’t ever remember a time when the geese flew in large flocks above me in the pitch black sky.  It was an eerie experience, sitting there under the stars, with occasional flashes of lightning from somewhere, while “their cryin’ voices trailed ahint them on the air —– .”

That line suddenly came to me – I had totally forgotten it – from a Scottish poem I came across several years ago.  It’s buried in the final stanza, and it’s appropriately titled “The Wild Geese”.  So by way of saying thanks to Neil for suggesting the splendorous 44 Boötis, here’s that last stanza:

And far abune the Angus straths I saw the wild geese flee,
A lang, lang skein o’ beatin’ wings wi’ their heids towards the sea,
And aye their cryin’ voices trailed ahint them on the air —–“
“O Wind, hae maircy, haud yer whisht, for I daurna listen mair!”

From “The Wild Geese,” by Violet Jacobs
The Scottish Poems of Violet Jacobs, Oliver & Boyd: Edinburgh, 1945, p. 83

Maybe the London born Skylight 100mm f/13 refractor I was peering into has a slight Scottish heritage hidden in it, or maybe there’s an uncanny quality wrapped up mysteriously in its marvelous mystique  –——- or maybe I was just fortunate to be in the right place at the right time.  Whatever it was —– it was kinda neat.

May yer skies be “maircyful” clair!  😎


One Response

  1. May 7th, 2012, at 2200

    After finishing the sketches shown above for 44 Boötis, I discovered one of the field stars to its northwest is also a double, with the tantalizing name of H 53. The magnitudes of that one are 8.9 and 10.9, separated by 87.2″ at a PA of 358 degrees (WDS 1999, and the WDS designation is 15025+4745).

    So I went in search of its faint secondary with a 90mm scope (an AT90EDT) in hopes of catching it before the almost full moon came up. I found it, just barely, with a10mm Radian (60x), and confirmed it with a 6mm Radian at 100x. The next night I came back with a six inch Celestron refractor, and had a better view of it in an 18mm Radian (67x), thanks to the additional aperture.

    Surprisingly, I was able to coax 44 Boötis into a tight figure eight at 250x in the 90mm scope. But in the eyepiece combination I was using (6mm Radian in a 2.4x Barlow) it was not only jumping all over the place, but was very faint — which is not surprising since I was pretty close the theoretical 1.3″ limit of its resolution.

    The H 53 designation caught my eye, mainly because I suspected William Herschel was involved here somewhere. Sure enough, he measured it on August 17th, 1781, with a separation of 86.7″ and a PA of zero degrees — so it hasn’t moved much in the 231 years since he cataloged it as H VI 53.

    For some reason, the WDS notes (scroll down a short distance) for this star state it could not be identified. I’m not sure what that is in reference to, since the star is definitely where it’s supposed to be, and the 1999 measurements are very close to Herschel’s original ones. And the Roman numeral “VI” to classify its separation matches up with the classification system he used.

    At any rate, if you’re up for an adventure, and you have the aperture for it, there is actually a third component to H 53. It’s cataloged in the WDS as L 9001, was discovered in 1911, and has a magnitude of 14.3, and a separation of 11.9″ at a PA of seventy degrees — with the last measurement having taken place in 2000.

    Let me know you do! 😉

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