Sunday, December 02, 2012

 

Unk's Messier Album III


It’s been a funny autumn, muchachos. Uncle Rod’s astro activities have alternated between 0 mph and 60 mph with nothing in between. One week I’d be down Chiefland way or at a star party like the just finished Deep South Regional Star Gaze. Next, I’d spend night after night gazing up at cloudy or at least hazy skies. This is not a prescription for starting big observing projects. Instead, Unk is focusing on a small one.

Some time back, summer before last to be exact, I started just such a little project, which I began documenting here and here. You can read all about it in those places, but the bottom-line-a-roony-oh is that I decided to follow in the footsteps of one of my favorite astronomy authors, John Mallas, who observed and sketched the whole Messier catalog in a series of articles in Sky and Telescope, “A Messier Album,” that ran in the late 1960s and which was later collected into a book, The Messier Album.

The idea for Unk’s Messier Album was a simple one: I would observe and sketch the objects just as John had done. I would compare what I saw with what Mr. Mallas saw. I would use a comparable telescope, but would employ modern eyepieces. There would be one major difference between our albums; John Mallas apparently did not like sketching open star clusters. There are really no drawings of galactic clusters in his album. I would have a go at them.

The photos in the book by astrophotography legend Evered Kreimer? Imaging has come a long way since the 1960s, but I had no interest in trying to duplicate Kreimer’s beautiful black and white photos, which I consider in some ways to be the definitive portraits of the Ms.

Howzabout the telescope? Mr. Mallas used the legendary Unitron 4-inch equatorial refractor. I dang sure didn’t and don’t have one of those beautiful star machines (though I still want one). What was in my stable that might be similar? A 5-inch Maksutov Cassegrain, my beloved Charity Hope Valentine, a Meade ETX 125PE. Charity is a 5-inch, not a 4-inch, and has modern hi-tech UHTC coatings, but given her rather large central obstruction (do NOT tell her I mentioned that, you-all), and the only fair-good skies at the Possum Swamp Astronomical Society’s dark observing site, I figgered the matchup would be fairly equal. Charity’s focal ratio is f/15, about the same as the old Unitron’s f/16.

Yes, I would use modern eyepieces. This little black duck ain’t gonna go back to keyhole-peering with Orthoscopics, much less the simple Unitron oculars Mallas likely used. John never mentions the eyepiece brands/designs he employed, but I assume they were the Huygenians, Ramsdens, Kellners, and Orthos that came with his telescope or were commonly bought by folks wielding f/16 achromats.

And so I hit the observing field the summer of 2011 with Charity to start running the Messiers. I had a freaking ball observing the spring/summer Ms, seeing what I saw that Mallas didn’t and vice versa, and gaining an ever greater respect for his ground breaking book. I especially learned to love his drawings. I found that even those that look a little weird and funky in daylight seem amazingly accurate by the light of a red flashlight.

And then? And then? Nothing. After the first two installments of “Unk’s Messier Album,” I stopped. Why? My excuse was that Charity needed a little work. Maybe that was an exaggeration. I had repaired her often reluctant Autostar hand controller before starting the Album Project, and all she really needed was a new battery in her LNT finder. The real reason I stopped was that The Herschel Project was slowly, ever so slowly, reaching its finale, and I was spending every moment of observing time I could squeeze out of my too busy schedule working on it.

And then The Herschel Project was suddenly done, culminating (for now) in my article about it in the August 2012 issue of Sky and Telescope. For a while it was fun being FREE. Trotting down to Chiefland with a C8 to do some simple visual playing around in the sky. Getting my Dob, Old Betsy, out to the DSRSG for some bright and easy and spectacular deep sky sights. But I’ve now begun to get the itch for some kind of big project again.

I actually have one in mind, one that I will start this spring, maybe, and which I will tell you about after Christmas. For now? It occurred to me that I had let my Messier Album slide to the point where I’d almost forgot I’d even started it. It seemed like just the thing for winter nights on the PSAS field, when your old Uncle gets chilly in a hurry and is liable to head for Chaos Manor South well before the stroke of midnight. Continuing The Album seemed especially attractive the week after Deep South. I was not in the mood to pack the 4Runner full of gear again right away. Easy - simple was the thing—but with a purpose.

To get Charity out of mothballs—it had been at least a year since she’d been out of her case—I would need to replace that LNT (“Level North Technology”) finder battery. “What the hail is an LNT, Unk?” It’s essentially a red dot finder, but it also incorporates a real time clock powered by a button cell when the scope is turned off, an electronic compass, and level sensors. Having the LNT is like having “semi-GPS.” Assuming you return to your previous observing site, you don’t have to enter nuttin’ into the Autostar HC. The location is already in there, and the scope gets time/date from the LNT. Flip the o-n/o-f-f to o-n, the ETX does a little dance, you center two stars, and you are on your way.

There is only one real drawback to the LNT widget: that little battery, a CR2032 cell. Meade, hilariously, said (the ETX 125 is, alas, now out of production) the battery would last “years.” Months is more like it. Six usually. You can still use the scope with a dead bat-try, but you will have to enter time and date manually, and what fun is there in that?

If you have one of the last of the ETX 125PEs, changing that battery is fairly simple. If you have an early one like Unk, one with the big eye-glass-spectacle lens LNT? Not so much. I was prepared for trouble and I got it. To replace the cotton-picking battery you have to disassemble the LNT, removing the two long screws that adjust its aim. That wouldn’t be too bad except for the fact that there are two small springs involved, and you have to be ever so careful not to break the wires that connect the LNT’s top to its bottom.

I put Charity on her tripod in Chaos Manor South’s front parlor and got to work. Taking the finder apart was fairly easy. At least I remembered which screws to remove. Even got the two springs out without incident. But then, in the process of finding a safe place to put ‘em, I dropped one. I did not panic, just ran and got a big Eveready flashlight, what my kid buddies and I used to call a “rabbit light” back in the 60s. No joy. I was just about to give up and go hunting in the junk box for a replacement when Chaos Manor South’s resident black cat, Thomas Aquinas, saved the day, putting his paw right next to the spring under the coffee table and looking up as if to say, “Here it is, Daddy.”

My praise for Tommy was effusive till a paw reached out for the spring after I’d placed it safely on the coffee table so he could repeat the process. Anyhoo, I got the finder back together only dropping the springs twice, with Thomas finding them both times. Got the LNT back together and returned Charity to her case after shooing The Old Manse’s other cat, Growltiger, out of the wonderful soft new bed he’d found. The foam in the case is tattered from where Tiger sharpened his claws on it shortly after it arrived nearly seven years ago, and I was not about to let him have another go. I spoke sharply to the feline, which did not impress him at all.

Then dark was coming on and it was time to load up for the Messier run. The sky was clear and there was absolutely no chance of clouds shutting Unk down—for once—but conditions were hardly perfect. Cooler than I like, if not cold, damper than me or Charity like, and there would be a crescent Moon hanging in the south-southwest till relatively late.

Motored out to the dark site and got set-up, which was just so wonderfully easy. Plunk down Charity’s tripod, bolt her to it (in alt-az fashion, naturally), open the 4Runner’s, Miss Van Pelt’s, tailgate and set the eyepiece box there along with the sketchpad and the big Plano tackle box I use for my accessories. That was the work of but a few minutes and I spent the balance of the time before Polaris peeped out shooting the breeze with my four fellow observers who’d joined Unk on this so-so evening. Oh, I did remember to mechanically realign the red-dot finder part of the LNT on a distant runway light (we observe from the edge of a private airstrip) before it got totally dark.

Once I could see Polaris, I got going, not with Charity’s alignment, but with her calibration. One of the most annoying things about Meade’s (now gone, I guess, since it’s been removed from the LX90) LNT finder is that after every battery change you not only have to mechanically re-aim the finder, you have to “calibrate sensors” so it knows where true north is, and, if you are smart, redo drive training, which informs the computer about the (copious) backlash of the ETX gears.

This is all more annoying than difficult. Powered up the girl after putting her in home position (tube level and cranked counter-clockwise to the drive base’s hard stop). I was pleased to see that the Autostar immediately picked up the time from the LNT, and I proceeded to sensor calibration, which involves nothing more difficult than centering Polaris in an eyepiece after the scope finishes pointing north. That done, I trained the drives. I find drive training more effective if I do it on a terrestrial object rather than Polaris. Why that should be, I don’t know, but I trained the ETX’s alt and az motors by centering a runway light and re-centering it after the scope slewed off it a couple of times in both axes.

Next up was go-to alignment. Charity picked Vega and Deneb, which I thought were a little close together, but…whatever… After I’d centered both the stars, which were only off a little bit after the scope stopped slewing, the Autostar said “Align Success.” But with Charity you really never know. Her neurotic nature—the reason for her name—means she can surprise, and not always in a good way. “Align success, huh? We’ll see about that.” Punched in M13, which was getting fairly low in the west, Charity made her good old weasels with tuberculosis noise and eventually stopped.

I inserted the Orion 20mm Expanse eyepiece (66-degree AFOV) and had a look. There was The Great One staring back at me and looking good nearly in the center of the field. Once again, I was impressed at how well relatively inexpensive oculars do in slow focal ratio Charity. And how good her contrast is despite a too big secondary baffle. Go-to? Miss had a good night. Anything I asked for from horizon to horizon, all night long, was somewhere in the field of the 20mm at 94x. Not always centered or even close to it, mind you, but somewhere in the field every time. In other words, my mercurial little girlfriend behaved herself.

Then it was time for what we’d come for, Unk’s Messier Album, starting with a long-time fave of mine. The matter in italics is transcribed directly from the audio log on my MP3 recorder, and the drawings are done in my usual fashion: rough sketches/notes at the scope, finished sketch as soon as possible after, and a little fine tuning in Adobe Photoshop. Oh, if you don’t have a copy of The Messier Album, I urge you to get one; having it at hand will make Unk’s Album articles a lot more interesting for you. The dates are the dates of the original publication of the columns in which the objects appeared should you wish to hit the Sky and Telescope DVDs. Finally, click on the pix for larger versions of my drawings...

M27 (September 1968)

M27 (NGC 6853), The Dumbbell Nebula, is looking good in the 20mm Expanse at 94x, even with a bright young Moon fairly close by. The basic hourglass/apple core shape is starkly visible, and, surprisingly, so is the football shaped nebulosity surrounding it. No hint of the central star. Improved even further with a UHC filter.

Hokay, what did John Mallas see nearly fifty years ago? I have gained a greater appreciation for his drawings, but not every one of them. His M27 is hard to figure. While he at least implies in the text that he saw the dumbbell shape, what he has sketched is a glowing, streaked rectangle. Frankly, I am not sure what Mallas saw on this long ago night. While I mostly beat the pants off him here, he did better my observation in one regard, mentioning that M27 was “quite greenish.” I’ve occasionally detected a little color in this nebula but it’s never been that prominent.

M71 (September 1968)

Sagitta's little globular star cluster, M71, NGC 6838, is lovely in the 20mm eyepiece. At first glance it looked like nothing more than a nebulous ball, but a little staring and it begins to resolve into tiny stars, first with averted vision and then with direct vision. At least five wink in and out of view as the (poor) seeing changes. The cluster's core at times seems to take on a triangular shape.

How did what I saw of the cluster compare to what Mallas observed? Looking at his drawing, it’s hard to say. He has drawn a large gray oval with a white chevron on one side. Three lonely stars are shown embedded within the oval, but that is it. His drawing is also harmed mostly by his reluctance to draw field stars. This is a very rich field, and without a few sparklers indicated, it just ain’t a very good depiction of what you will see in any telescope.

John’s text is a little more illuminating, allowing that the cluster was “beautiful,” but that he only saw a few stars resolved. Apparently what I interpret as a triangle-shaped center, Mallas saw as a brighter V superimposed on the core.  Overall, I’d say I saw more, including more resolved stars, than he did.

M57 (August 1969)

Certainly ain't gonna see The Ring Nebula’s, M57's (NGC 6720), central star with a 5-inch, but I don't see the brighter star near the edge of the ring, either. Nice looking, though, and obviously elongated, with the hole easy. The donut hole is clearly filled with nebulosity, and, as I continue to observe, including with an OIII filter on the 15mm Expanse (125x), I begin to see a brighter streak in that nebulosity.

I didn’t think much of Mr. John’s M27 and M71 drawings, but his M57 brings it all back home. Not only does this excellent sketch indicate very marked brightness variations along the ring, he shows one of the embedded stars (not the central one, of course). While his drawing is hurt by his usual reluctance to show field stars, it’s clear he got a better look at M57 than I did. Maybe because, as he tells us, he pumped the Unitron’s power up to 250x. Low power is NOT always best for the deep sky, campers.

One puzzling thing? Mallas says the Ring is a “challenge to the observer.” I’ve never found that to be the case. Sure, you see more with larger aperture and higher magnification, but this planetary ain’t a challenge for even my Short Tube 80, Woodstock, who shows the dark hole, at least, with aplomb.

M56 (August 1969)

M56 (NGC 6779) is bold--for M56, anyway. This subdued glob is grainy and even shows a few resolved stars across its core. Triangular center. Large, elongated haze haze around that. Well I remember how I used to struggle with this globular with my 4-inch Palomar Junior back in the 1960s.

I’d say John M. and I pretty much tied regarding what we were able to pick out of M56. He notes its subdued nature, but goes on to tell us about and to show in his drawing a goodly number of resolved stars. One oddity is that his sketch shows a dark, thin oval void at the center of the cluster. I’ve never seen anything like that visually, and it is not visible in images as far as I know. Perhaps it was a result of too little aperture, too much magnification, straining for detail in the dim and loose cluster center, and maybe seeing that wasn’t all it could have been.

M29 (September 1969)

Open cluster M29 (NGC 6913) in Cygnus is near the zenith, but Charity, who sometimes has trouble with objects at high elevations, put this one in the field without trouble. It is one of the poorest Messier galactic clusters. In the 20mm eyepiece it is a small dipper or "Pleiades" shape formed by a few medium bright stars. Certainly nothing to write home about.

I can’t compare my drawing of M29 to John’s since he, as above, resolutely refused to sketch the Messier galactic clusters. It is clear from the text that he and his big Unitron saw just what I saw with Charity, though. He refers to M29 as forming a “stubby” dipper, which is as good a description as any, I reckon.

M39 (August 1969)

Most folks would say Cygnus' other Messier object, M39 (NGC 7092), is as poor as M29. It's kinda nice, tonight, though. A triangle of bright stars filled with a scattering of dimmer but still prominent suns. If it were just a little smaller it would be quite a sight. As is, its 32' size is too big to make it look outstanding in an f/15 scope. The 20mm Expanse takes in the whole cluster, but without much dark space to frame it well.

John Mallas and I had exactly the same opinion of M39:  it’s a nice triangle of bright stars that is underappreciated by many deep sky observers. He mentions seeing 25 stars brighter than magnitude 10.5, which is about how deep I went, though I didn’t draw every single cluster star.

And that was that. I could have gone on to spectacular M15, or maybe to M30, but I thought it best to put on the brakes. Mallas usually limited himself to just a few objects per column, and that seems about right to me. The joy of doing the whole Messier this time will be in the leisurely contemplation of its wonders.

It was still early and despite the steadily falling temperature Unk wasn’t quite ready to throw in the towel. Especially on a night when Charity was cooperating. Not only were her go-tos decent and her tracking at least acceptable—I had to re-center objects once in a while, but only once in a while—her images were very nice even in the poor seeing. All things considered, I’d say she wasn’t giving up too much to a C8 on this evening. What to look at next, though, was the question. Jupiter was out. A quick glance at him revealed the King to be a writhing mess. The big guy was too low in the sky yet, and the seeing way too bad even for a 5-inch.

Where then?

How about the storied Seventh Planet? I take at least a quick look at Georgium Sidus every time he is in the sky. Yeah, the seeing was punk, but that wouldn’t matter. It wasn’t like I was going to see detail on this distant giant with Charity, anyhow. What I did see at 125x was a nicely resolved if tiny sea-green dot and that was enough.
After spending some time contemplating Sir Willie’s world, it was “onward.” One of my buddies was exclaiming about how surprisingly good the Helix Nebula, NGC 7293, was despite its location fairly near on to the Possum Swamp light dome. How would this giant planetary nebula look in Charity? Would it be visible at all in a 5-inch? Indeed it was. It was clearly there in the 20 Expanse, though I had to hold my mouth just right to be sure. The addition of my good, old Lumicon 1.25-inch OIII filter made averted imagination no longer necessary. The Nebula and its donut hole were easy. I recalled I used this very filter to get my first really good look at the Helix with a C8 back in 1995 at the Deep South Regional Star Gaze that year.
And so it went for a while, me mashing Autostar buttons and sending Charity to everything I imagined would look good in a five-inch. One of the standouts, I reckon, was Sculptor’s titanic galaxy, NGC 253. No, it did not look as good as it had the week previous in my 12-incher, Old Betsy, at the DSRSG, but good nevertheless, stretching its long body across the field and showing off quite a few of its dark, mottled patches.
When I couldn’t think of anything else, I took a “Tonight’s Best” tour with the Autostar. Saw a few more cool things, but, as always, I was bemused by some of the Autostar’s choices. I mean, Quasars in an ETX?  Tour done, I had to admit I was weary and I was cold. Maybe the late (for Unk) nights at DSRSG the previous week were catching up with me. One quick peep at M42, which was now high enough to bother with, if not even close to being out of the pea-picking light dome, and I pulled that cursed Big Switch. Charity went into her case, tripod and case went into the truck, and I was ready to roll in ten minutes.
Back within the comforting walls of Chaos Manor South, in our cozy den, cable TV cranking and a portion of Yell close at hand, I contemplated the ETX. I love Charity and am a little sad there will not be any more 125s. Yes, there is still an ETX 90, but it has been dramatically changed and cheapened. It is not even clear to your old Unk whether, given Meade’s current and continuing spate of problems, there will be any Meade scopes of any kind much longer. I do know many of us will miss the legendary ETX 125. Celestron’s NexStar 5 is less quirky and more solid, yeah, I’ll admit that, but there is never, ever going to be a scope with as much personality—even if it’s a slightly warped one—as Charity Hope Valentine.
Next Time:  Rocket City Thanksgiving…


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