Sunday, March 21, 2010


Unk’s Mini Messier Marathon

I don’t have to tell y’all what a “Messier Marathon” is, do I? Oh, you’re the wettest of wet behind the ears novices? OK. Here’s the straight poop. When you hear the folks down to the club goin’ on about a “marathon,” they ain’t talking ‘bout no foot race. The marathon they are jawboning about is a hugely popular feature of amateur astronomy that’s practically become a Rite of Spring for lots of us.

“Messier Marathon” was something that first popped-up in the 1970s, appearing spontaneously at various clubs around the country at the behest of many different “discoverers.” If any single person can be credited with popularizing the Marathon Idea, it’s probably comet hunter Don Macholz; he at least helped bring the concept to the attention of the amateur community at large.

“Enough beating around the bush, Unk! WHAT CONCEPT?!” That it’s possible to see all 110 M-DSOs (if you count a whole 110 Messiers, which some folks do and some do not ) in one night at one special time of the year. What’s the special time of year? There’s a window of opportunity centered on the Spring Equinox that stretches from mid March through early April. Not that catching ‘em all is easy, mind you; it helps to be at a latitude of no more or less than about 25 – 30 degrees north. Even given good skies and optimum latitude, there are challenges.

The challenges mostly come at Sunset and Sunrise. Sunset is toughest. There, you’ll have to catch the notoriously faint face-on Sc spiral galaxy, M74. This fuzzie, which ain’t called “The Phantom Galaxy” for nothing, ain’t always easy when it is high in the sky, and when you put it low on the horizon in the dusk it becomes insanely tough. M33 is right behind it. That Local Group galaxy is not normally real hard, but it gets that way in a right quick hurry when it’s low and in a less than dark eyepiece field. In the morning, the usual culprit is M30, the odd-looking globular star cluster in Capricornus. Like M33, it’s not a difficult object, but when circumstances put it deep in the dawn, it will be tough. Very.

The rest of the list? Most are falling off’n a log easy. I do sometimes hear folks complain about The Realm of the Galaxies, the rich galaxy fields of Coma and Virgo, but if you’ve spent some time there before, and have a decent set of charts (best is a program like SkyTools or Megastar running on a laptop), it ain’t that bad. No need to freak out in Virgo, anyhow, since you can purty much take your time. Once you do them galaxies, there is a significant break before the summer objects begin to rise high enough to mess with. Take your time, back-track if’n you have to, and get ‘er done. After Virgo-Coma, it’s a tour of the summer objects, early and late, and a couple of fall fuzz balls. Nothing even close to challenging till you come to the aforementioned Capricornus Cluster.

You do need to keep on schedule if you want to have plenty of time on the back end and not miss anything in Sol’s glow. What I’m a-telling you is that there is an optimum search order. Luckily, there are numerous websites with lists of the Messiers in Marathon Order. Some planning-type astro computer programs, like RTGUI, which we discussed last week, even have readymade Marathon lists. The best thing of this type I’ve found, though, is Larry McNish’s free online Messier Marathon Planner. Bring up this interactive web page, input your latitude, longitude, and date and out comes a search list optimized just for you. This not only includes notes and specs for each object, but even thumbnail images (if you wish) for each M.

What’s Unk’s Messier Marathon history? Come si, come sa. I’ve done it the hard way, with Telrad and finder scope, a time or two, with my best being “everything but M30,” I believe. Mostly, though, I’ve taken the easy/lazy way out, pursuing ol’ Chuck’s cosmic lint balls with go-to, digital setting circles or, like this past weekend, analog setting circles. I already hold an Honorary Messier Certificate from the Astronomical League, so the attraction for me ain’t the hunting, but the seeing. How you run the marathon is up to you. There ain’t no rules. Leastways unless you are after your Messier Certficate. If so, you need to follow the strictures laid-out on the AL M-Club website.

Be all that as it may, I set out to do this year’s Messier Marathon this past weekend. Or, actually, I didn’t set out to do it. My goal, as I tole y’all last time, was to get The Herschel Project cranking again. That fell through. The main reason was the weather forecasts. For days, the damned weather-goobers had been predicting mostly cloudy for Saturday night. If there’s one thing I’ve learned in recent years, it’s that if the forecast even mentions clouds, you can expect plenty of ‘em. Ironically, they got it mostly wrong this time, but that is, shall we say, “unusual” of late, especially in the time of an el nino (whatever the frack that is).

Given the projected weather, I set the H Project aside. I hope to have quite a few days down in Chiefland next month or the one after to go for the spring sky, so it warn’t no tragedy. Whatever the weather, I wanted to see something, though, and I began to think “Messier Marathon.” I did not plan to do the Whole Big Thing, though, understand. The lovely Miss Dorothy had been gone to a conference in Ohio, and I’d been Up North for a couple of days before that myself. I wanted to be back home at least shortly after Miss D. arrived on Saturday night. I’d do a mini-marathon. All the objects up to Virgo, I figgered—about half the list.

The telescope? Since it didn’t sound like the consarned weather  would be so hot, I forgot about the C11. Even a C8 seemed a bit much. Same sure went for Old Betsy, my 12.5-inch Dobbie. I considered Sweet Charity, our ETX 125, the star of last week’s blog, but I thought a little more aperture might be appropriate. What seemed right was my 8-inch f/5 Dobsonian, Old Yeller. You can read all about him at that link, but the short ‘n sweet is that he is a cool-looking truss type scope built around a Synta primary I had. No digital setting circles. He has analog altitude and azimuth ones.

You can learn more about setting circles for Dobs here, but there’s really not much to tell. You make a graduated azimuth circle, attach that to the base of the scope somehow, and mount some kind of angle indicator on the tube. Since the sky is forever in motion—well, the Earth is, anyhow—you’ll need a way to calculate current altitudes and azimuths of objects. Today, that is laughably simple. Almost any PC astronomy program will do it for you.

So will the increasing number of astronomy programs designed to for PDAs (like the Palm Pilot) and similar devices. I chose to use SkyVoyager, a wonderful planetarium that runs on my iPod Touch, and which will also run on an iPhone or on the upcoming iPad. One of these days, I may devote an entire blog to phone/pod astro-ware, but I will say rat-cheer that the astronomy-ware coming down the pike for Apple’s “mobile devices” is both beautiful and useful.

I had made two changes to Ol’ Yeller’s setting circle system since the last (and only) time I’d used it. Most important, I’d built a leveling platform out of a piece of scrap plywood, some bolts and T-nuts, and some furniture glides. When using altitude/azimuth circles, you’ll find that the scope must be close to level. If it ain’t, objects at low elevations will be easy to find, but those near the zenith will be way, way off. I ran into that big time last time, and knew I had to come up with a way to level Yeller. Construction of my platform was simplicity itself: I cut a square of plywood, drilled a hole in each corner, inserted a T-nut in these holes, threaded a bolt through each T-nut, and affixed furniture glides to the bolt with nuts.

The only other thing I did was replace my analog angle indicator with a battery-powered digital job. The analog indicator, which only cost a couple of bucks at Harbor Freight, did OK, but its gradations were fairly rough, one degree increments. I figgered a digital unit (also from Harbor Freight) reading tenths of a degree ought to improve my accuracy. Danged good thing I decided to check the digital indicator, which I’d bought months and months ago, on Friday afternoon. Stone, cold, dead. Apparently it draws a little current even when not on. Unfortunately, them dead batteries was dadgummed little CR2032 button cells. The three required would set me back some 15 bucks at Walgreens. Penny pinching ol’ Rod decided to order some off’n eBay instead, and just use the analog job for Saturday’s marathon.

As always when using a Dob of this size, setup was laughably easy. Since I’d added the leveling platform to the mix, there was a little more to it than just plunking down the rocker box and ploppin’ the OTA in it—but not much. I set my platform on a reasonably level piece of ground, checked it with a bubble level, adjusted the feet as necessary by screwin’ ‘em in and out, and proceeded to the plunkin’ and ploppin’. I’d eschewed my laptop, bringing only the iPod, so all I needed as an observing table was a small collapsible camp table that’s just a little bigger than TV tray size. Unloaded that; my eyepiece box; and a drybox containing my filters, flashlights, and assorted accessories and I was ready to go. Total time? Maybe 10 minutes—tops.

Red filtered reading light is used for illumination.
How about alignment? The only alignment required for an alt/az setting circle rig is to aim the scope at true north (at Polaris) and set the azimuth circle to zero. If Polaris is not visible, you can use any star, but you will have to use the computer to find the luminary’s current azimuth. Polaris is good because it’s reasonably bright and doesn't change. You don’t have to set or align anything for the altitude axis, assuming your angle indicator works right. Total time required for alignment? Maybe two minutes.

What now? A test. It wasn’t fully dark yet, but Orion was shining in the south, and that peculiar fuzzy star in his sword was visible. Started SkyVoyager by poking its little icon on the screen of the iPod, and selected “search,” “Messier Objects,” and “M42.” In a second or three, up came a screen loaded with information about the Great Nebula, including its current altitude and azimuth. I moved the scope till the pointers were on the given coordinates, inserted the 13mm Ethos, and saw—NOTHING.

Probably the most important thing I learned during this evening’s run was the need to be reasonably precise with the setting circles. The display on the iPod read “193 degrees, 42 minutes azimuth,” yet I just blithely moved the scope till the pointer was somewhere close 193. Resetting so that the azimuth pointer was ¾ of the way between 193 and 194, and being as precise as possible with the (rough) altitude scale as well, placed M42 in the field of the 13mm. M35 at the zenith would be the kicker, though, and would show whether my leveling platform helped. I got the coordinates for the Gemini cluster, set the scope as close to them as I could, and there was M35 looking sweet in the TV Ethos.

What was the short and long on the alt/az setting circles? They worked. But using ‘em seemed like a lotta trouble. I found myself setting and resetting numerous times as I hunted dimmer Ms. The brighter objects were easy enough to run down by means of a little aimless slewing around the coordinates. The less prominent Messiers, like M108 and M97, though, seemed to require an inordinate amount of fooling around. That’s the way it seemed, anyhow. The evening’s total, 40+ objects, was actually a little higher than what I’d done the previous week with Charity’s full go-to system in about the same amount of time. Maybe all that hunting was more perception than reality. Finally, I believe getting the digital angle indicator working will improve my accuracy.

The most surprising take-home, however, didn’t have a thing to do with the finding system, but with the telescope. I was gobsmacked that most Messiers didn’t look much better—if any better—than they had in the considerably smaller ETX. Yes, three inches more ought to make a difference, but under my hardly optimum sky conditions, and given the fact that I was not hunting truly faint fuzzies, almost all of ‘em looked about the same as they had in Charity. That in mind, I might in the future lean more to the ETX on so-so/quick look/short time nights. She not only offers go-to that usually requires no slewing around to find targets, she brings all the cool features and utilities inherent in her Autostar hand controller to the table. The main thing in favor of the 8-inch f/5 (in addition to the fact that she’s a pretty thing) is that she can accommodate my Ethos eyepieces. Even the 1.25-inch/2-inch Es are problematical for Charity’s focuser due to the design of her rear cell.

The biggest hit of the evening was undoubtedly SkyVoyager. Yeah, the iPod’s screen, though large for this type of device, is purty tiny for my late-middle-age eyes, but I didn’t feel a bit deprived. The program can do anything a full-size planetarium can—and more—and the iPod’s screen, if small, is surpassingly clear and sharp. Add-in the new wireless wi-fi go-to system from SkyVoyager’s maker, Carina, and maybe run the program on the big screen of the upcoming Apple iPad, and a lot of us may think about givin’ up our Windows laptops for good.

Having made friends, more or less, with the setting circles, it was time to get down to bidness. The following objects were observed in a relatively short window from about seven to nine-thirty PM. My most frequently used eyepiece was the 13 Ethos, though I would occasionally switch in the 35mm Panoptic when I was having trouble locating objects and when I was in a relatively dark part of the sky that would allow the big Pan to shine.

The Western Horizon Huggers

M74: Ha! I convinced myself I saw a trace of this face-on Sc spiral low in the gloaming. Maybe. Probably not. I dunno. This is the marathon’s evening heartbreaker, and I don’t believe I got it this year. I did see it without tremendous difficulty last year, but that was with my Sky Commander DSC-equipped 12.5-inch.

Despite normally being an easy target, M33, 25 degrees above the horizon and in the Sunset glow when I went after it, was a pain. A maybe/probably.

M77: Now we are a-talkin’. Not much to look at of course—fuzzy star—but there indisputably.

The Andromeda Nebula, M31, and her little sister, M32, were like shooting proverbial fish in a barrel.

M31’s other nearby satellite, M110, is larger than M32 and saddled with a lower surface brightness and was a surprising challenge. Got it, but barely.

M52: Only 17-degrees high in the west, but easy to see. Thankfully, it’s a bright and prominent open cluster.

Out of the Murk

Galactic cluster M103, about 30-degrees up, was extremely attractive. So nice I wanted to linger. But that is not in the cards on a Messier Marathon night.

M76: The Little Dumbbell was easy. Even showed off its twin-lobed nature.

M34, a large open cluster in Perseus, was nicely framed in the 13 Ethos.

Didn’t need a scope for M45’s Pleiads.

M79: Back down closer to the horizon for thisun, but not much of a problem. A round fuzzball in the 13mm, and didn’t show much in the way of resolution.

M42 and M43? Amazing and amazingly easy—nuff said.

Found M78 with just a little poking around. Very prominent around two stars.

M1 was quite good, showing off its “S”/lightning bolt shape. I was gratified that my analog circles put this in the field; obviously my leveling platform was doing its job, since this fairly dim supernova remnant was pretty derned high up.

M37 was superb. Seemed to form a spiral pattern around its “central” red star.

M36: Never been a favorite of mine, but I must admit this Auriga open cluster looked sweet on this night.

The third Aurigan, M38, is probably the weakest of the constellation’s trio of Messier opens, but it was nice enough in the 8-inch f/5.

Had to switch to the 35 Panoptic to make sure I was on M41. It is very large and relatively sparse—more of a binocular object.

M50: This open cluster is respectable in the Panoptic, if nothing to write home about.

M47 looked pretty much like it did last week in the ETX. Big and a little sparse, that is.

Galactic cluster M46 with its planetary nebula, NGC 2438, was cool. The nebula was a little more distinct than it was in Sweet Charity, but there was not a world of difference. Good enough that I replaced the 35 Pan with the 13mm Ethos and a Celestron OIII filter for a better look, marathon or not.

M93 in Puppis was good-looking, if not good-looking enough to make me want to hang around longer.

The large open cluster M48 is about ¾ degree across, and would probably have looked better in the 35 or 27 Panoptic. But I moved on, instead.

M44, The Beehive Cluster, was visible (barely) as a misty patch near zenith with my naked (huh-huh, huh-huh, he said “NAKED”) eyes.

Cancer’s other open cluster, the far more compact M67, was easily captured with just a little fine tuning of my aim. This ancient (for a galactic cluster) group of stars is one of my all time faves.

M81 and M82: These two beautiful galaxies fit easily in the field of the 13mm Ethos.

Good, old Owly.
I thought M108, the edge-on galaxy in Ursa Major, would be easier to see with the 8-inch than he was last week with the ETX 125. Nope. Considerable searching around and resetting was required. Fairly heavy sky glow approaching the eastern half of the sky, so the 35 Panoptic wasn’t much help.

In contrast to M108, M97, the Owl Nebula, was reasonably easy, if not any better, really, than he’d been in Charity last time.

M109 was a hassle. I spent what seemed like at least ten minutes running it down. Not that dim, but easy enough to pass over in the increasingly bright background sky.

M106 took at least as much effort. When found, about the same as in the 5-inch ETX—an elongated blob.

Once I un-dewed the secondary with my dew zapper/12vdc hairdryer (didn’t have the Kendrick turned up enough, I reckon), M95 and M96, two Leo galaxies, were easy, if not much to look at in the light dome.

Finally, another easy one, M105! This elliptical galaxy and his two companions looked about the same as what I saw in the ETX the Saturday before.

M65 and M66: These Leo fuzzies were nicely framed and easy to make-out in the 13 Ethos.

The Sunflower, M63, finally fell to Ol’ Yeller after considerable huntin’ around.

M101: Did I see this legendarily challenging Sc galaxy’s nucleus? I think I did. Perhaps, anyhow.

Wheeeew! Much, much easier is M94, a small Canes Venatici galaxy with a bright “peculiar” nucleus.

The Sunflower.
M3 was a mere 26 degrees above the horizon and in the worst area of the sky. At the fairly low power delivered by the 13mm eyepiece, it was just a round—if bright—spot.

The Blackeye, M64, was also down in the trash, but easy to find. No more sign of the galaxy’s black eye dust-spot than there was in Charity.

And that was the logical stopping place for an early evening’s Messier hunt. It would have been at least another hour before Virgo’s horde began to lift substantially out of the light dome. In ten minutes, Ol’ Yeller was in the backseat and I was on my way back to Chaos Manor South to welcome the wonderful Miss Dorothy home.

What else went on over the course of the week? I had the distinct honor and privilege of doing my two-hour presentation, The Past, Present, and Future of the Schmidt Cassegrain Telescope, for the good folk of the Chester County Astronomical Society way up yonder near Philadelphia, PA. The trip, a quick one, up Tuesday and back down Wednesday, was made most pleasant by the hospitality of this outstanding club, whose members forgave Rod his corny jokes, occasional mistakes, and hillbilly manners. Special recognition is due two outstanding CAS amateurs, Ann and David Hockenberry, who not only retrieved Unk from the airport, fed him lunch and dinner, and hauled him around, but also opened their home to him. Thanks, guys! Your kindness made it easy to forget the depredations of U.S. Airways. (Them suckers wanted five bucks for a two-bit bag o’ peanuts!)

Stop the Presses! The cute little Orange Tube Celestron C90 who visited Chaos Manor South couple of weeks back has returned as a permanent resident of The Massive Equipment Vault. Details soon.

Hi, Uncle Rod.

Just a couple of thoughts. When using Dobsonian setting circles, one advantage of RTGUI is that it is a true real-time program, so its altitude and azimuth values are continuously updated. If you're watching an object for a while, maybe at a star party, and somebody bumps the telescope after ten minutes, or it drifts away and you lose it, other software will be giving you the Alt-Az from ten minutes ago (until you re-load the data). RTGUI will be displaying the coordinates that will work right now.

Don't pay so much for those little 2032 batteries!!!! Dog-gone Walgreen's, no way. Some of the 99 cent or dollar stores sell those batteries, often in a package with two or three of them for a buck. Also, the Dollar Tree Stores (which I believe are nationwide) sell two little electric candles, each with a 2032 in it, in a package for $1. Take out the batteries and throw away the candles!
Post a Comment

<< Home

This page is powered by Blogger. Isn't yours?

stats counter Website Hit Counters