Sunday, August 07, 2011

 

The Herschel Project Night 26: 398 Down, 2 to Go


Sometimes I wimp-out, muchachos. Especially in the summertime after a long, hot day segues into late afternoon thunderstorms. Even if it doesn’t rain at the dark site, you can bet the humidity will spike up to the intolerable level. And don’t forget the bugs, oh no. After a good rainy stretch like we’ve been having down in the swamp, you might as well hang a sign around your neck, “Soup’s on!” for the hordes of mosquitoes. Yeah, I know, my rule is supposed to be “head for the dark site if’n it ain’t raining,” but it’s not always easy to convince myself to stick to that at the height of a Possum Swamp summer.

There was one large incentive for me to give it a try this past Saturday night, though: I lied to y’all. Not on purpose; I just got confused. Nevertheless, I was wrong when I said I had finished both the Herschel I (400) and Herschel II. The II, yes, the 400, no. Imagine my embarrassment when I took a look at the list for the first time since me and Miss D. returned from our latest Chiefland expedition and discovered I still had four Herschel 400 objects to go. Two of these were in Lynx and would be dicey to the point of impossibility, setting well before it was good and dark. The other two, one in eastern Hydra and one in Libra, could be easily picked off.

Naturally I also wanted to continue the Big Enchilada part of the Herschel Project, a.k.a. “The Whole Big Thing.” That is my quest to observe all the (nearly) 2500 objects discovered by my heroes, Will and Lina Herschel, in the 18th century. Where do I stand with that? Coma Berenices, that huge forest of galaxies, is still not finished, but it would be too low and in the horizon mess by dark. Which made my prime target galaxy-laden Boötes. Even at the tail end of July, the Herdsman is still well-placed for observation. If I closed out Boötes? Our friendly summer snake, Serpens, would be on his way down and there were galaxies I needed in his “Caput” half.

Like they say on the pea-picking WTBS late at night, BUT THAT’S NOT ALL! I also wanted to have a look at a peculiar little comet, C/2009 P1, Garradd. What makes this little visitor, discovered by Australian Gordon Garradd a couple of years ago, unusual? It would be pretty bright, around magnitude 9, the estimates I read said, and will continue to brighten steadily till it peaks late this winter. It probably won’t be better than mag 6 at its height, but it will remain easily visible in small telescopes for months and months, which is the unusual part.

How would I do all these things? I expected haze, heavy haze, and maybe intermittent clouds. As I discovered on nights 23 and 24 down Chiefland way, you see faint fuzzies under those conditions with a deep sky video camera. I wasn’t about to lug out my NexStar 11, Big Bertha, on a night such as this, however. It would be an evening for my trusty 1995 C8 OTA, Celeste. Which mount? I was tempted to load up the Atlas, but the thought of all the sweat that 60+ pound GEM would cause meant it was no more attractive a proposition than huffing and puffing with Bertha.

Which left my Celestron CG5 German equatorial mount. Some folks sneer at this plebian Chinese-made GEM, but I love mine. It has literally never missed a beat in the almost seven years I have owned it. Tracking is easily good enough for the 10-second exposures of my Stellacam II, and with the f/10 OTA focal-reduced to about f/4, it is trivial for the mount’s computer to put anything I ask for on the tiny Stellacam chip.

Course, if you are a-gonna do video, you gotta drag out all the support gear: DVD recorder, video display, inverter (for AC for the recorder), and a big trolling motor battery. I’d also need my netbook for SkyTools 3 and NexRemote. Lotsa cables to hook everything up. The observing table to put all the astro-junk on. Couple of jump-start batteries: one for the CG5, and one for the Stellacam II and the DewBuster (I predicted it would be an uber damp night). Yeah, it would be a hot time in the old town tonight. I just hoped I’d be rewarded with some hot observing.

After an uneventful drive to the west of our little burg, I arrived at the Possum Swamp Astronomical Society’s dark site, and was pleased to see a goodly number of hard-core observers had turned-out despite the distinctly uncomfortable conditions. In addition to yours truly, six other folks were in the process of setting up various and sundry telescopes.

The weather? Instead of beginning to look worse as it often does as sunset approaches on summer eves, it was actually commencing to look better. A couple of thin patches of clouds, but they seemed to be departing, taking much of the haze with ‘em. It was hot enough, sure, still near 90 as the day ended, but it did not feel as bad as I’d feared. If there had been a breath of breeze it would almost have been comfortable.

If not for the skeeters. I wasn’t greeted by clouds of ‘em, but a couple dive-bombed me the minute I got out of Miss Dorothy’s Scion Xb (the old reliable Camry decided not to be so reliable and was in the shop). I was prepared. First thing I did was load a pad and a butane cartridge into my Thermacell bug-ejector. After it had run for about 10-minutes, every biter within five meters headed for the hills.

With the sun sinking, I needed to get on the stick. I didn’t rush in the heat, but I didn’t waste time setting up the CG5, getting Celeste on it, mounting the Stellacam II, and cabling it all to the DVD recorder and netbook. Retrieved my Wireless Wingman gamepad I use as my “HC” with NexRemote, and I was ready to go.

While waiting for alignment stars to show themselves, I strolled down the field to the setup of good buddy Kent, who had brought out a brand-new rig, an Explore Scientific 80mm APO and an Orion (Synta) Sirius (HEQ-5) mount. Ain’t nothing sweeter than a new scope, and I was pleased to find two on the field this evening. New club members Tommy and Robin had brought out their first serious scope, a Celestron NexStar 8se.

What did I think of the new gear? It looked GOOD. The APO, in particular, with its pretty white tube, big 50mm finder, and cool two-speed focuser set my mouth to watering. The NexStar warn’t no slouch, either, sporting a retro-orange tube and clean lines. I was looking forward to seeing how well the new telescopes worked, but, if looks were any gauge, I thought they would both be winners.

With Polaris now visible, I headed back to my rig, centered the North Star in the hollow polar bore of the mount as a rough alignment, fired up the computer, started NexRemote, brought up the Stellacam II, and switched on the vid-monitor. Go-to alignment takes a little while with the CG5, since I not only do the two alignment stars required, but add four calibration stars to ensure the mount is accurate all across the sky.

That done, I run the polar alignment routine in the HC to keep star-trailing non-existent in 10-second exposures. I use the old v1.12 CG5 firmware (selectable in NexRemote) most of the time, so polar alignment is very simple. The scope points to where it thinks Polaris should be; you use the mount altitude and azimuth adjusters to center the North Star in the finder and in the eyepiece (in my case, on the video display) and you are done.

Well, almost. Since I moved the mount’s head a fair distance to polar align, I’d need to redo the go-to alignment, doing the same 2+4 stars over again. Technically, you probably don’t need to redo all the calibration stars, but centering ‘em up with the wireless joystick is so golderned easy I usually do all four, anyhow.

A dozen stars plus Polaris centered, Celeste, in her Microsoft Mary voice (thanks to NexRemote), intoned “Alignment Success.” Y’all know me, though: I don’t care if it’s Charity Hope Valentine, Big Bertha, or Celeste, it is always the Reaganesque “trust but verify.” I punched “M 003” into the virtual HC on the netbook screen, the CG5 made its usual weasels-with-tuberculosis sounds, Celeste said, “Target acquired!” and what I saw on my screen was…NOTHING.

Then one of my few remaining non-Rebel Yell soaked braincells sputtered: “Rod, you dummy, the camera is still set to 1/30th-second exposures.” I walked over to the mount, snatched up the Stellacam II (wired) hand control I affix to a tripod leg with Velcro, and cranked it up to five seconds. Turned back to the monitor, and M3 was a great big ball of beautifully resolved stars sittin’ pretty in the center of my field. As I said the other week, I am continually gobsmacked more folks don’t rave about this spring wonder. Anyhoo, dialed the camera exposure up to the next and last setting, which yields 10-seconds, and prepared to go after the first H-400 sprite.

Before I did that, though, I turned a critical eye on the sky, which was now on its way to “good and dark.” Not only had scads of stars turned on, the cotton-picking Milky Way had begun to glow. It is not unusual to see it from our dark site, but it is usually more subdued than it was on this unexpectedly beautiful night. Before I called it quits, plenty of detail was visible in it, including the Great Rift. Just goes to show you never can tell. Dang good thing I didn’t decide to stay home watching Man versus Food.

While the sky was now good and clear, it felt damper than ever. The Telrad fogged up before I could finish the mount’s alignment, so I cranked the DewBuster to its 10-degree setting and hoped. Seeing? Not great, but not bad, either.

I squinted at SkyTools, and noted the two Lynx objects I needed were still visible. Hot dog! I sent Celeste that-a-way. She slewed and she slewed, with the tube winding up pointing west and just a little higher than flat-out horizontal. No way. I put on my glasses and had a second look at the program. I had forgotten to punch up the RealTime tab, which will show only the objects in the list that are currently observable. Shucks. Both Lynx galaxies were for all practical purposes gone. The Hydra and Libra fuzzies were still available, though.

As always, the matter below in italics is transcribed more-or-less exactly from my (audio) observing log, galaxy types are given according to the de Vaucouleurs system when possible, and I used N.E.D, the NASA extragalactic database, as my prime reference. Also as before, the images are simple alt-print screen grabs of single video frames.

The Herschel 400

NGC 5694 (H.II.196) is a tiny globular in Hydra. Magnitude 10.1 and 4.3’ in diameter. This is one of the more distant globular clusters, and Sir William and Lina were unable to resolve it. Its Shapley – Sawyer Class was once considered to be “I,” the most concentrated, but is now thought to be a VI, which is still tight for resolving stars at its considerable distance.

Unlike Sir William, I can make out a few stars and what looks to be a couple of chains of barely resolved stars off to the northeast. But, man, is this glob small.

NGC 5897 (H.VI.8) in Libra is a much more accessible globular—it’s well resolved, anyway. This is a Shapley – Sawyer Class XI, meaning it is incredibly loose on the 1 – 12 scale, making it almost the opposite number of NGC 5694. Magnitude 8.4 and 11’ in size.

Nice, large globular cluster in Libra. Looks very much like a rich galactic cluster. It shows very good resolution across what there is of its core.

Two down, then. I’ll get that Kitty’s two hangers-out this winter, I reckon. H400 work done, I took a short break. After all the rushing around to get the setup finished by nightfall, I was slightly overheated and weary. First order of bidness was guzzling the Monster Energy Drink I brought along in my little cooler. It was wet, it was tasty, and it immediately perked me up. Wasn’t quite ready to start the Big Enchilada, though, so I hoofed it over to Kent’s set up to see how the ES refractor was doing.

I knew the little scope’s owner intended to do some imaging, but I hoped I could cadge a look first. I was in luck; Kent was using the SynScan’s Tour mode to look at eye-candy. Peeper to eyepiece and what should I spy but the good old Dumbbell Nebula, looking great. Sharply defined and brighter than I thought it had a right to be in an 80mm. I pronounced the rig a winner and headed back to my end of the field.

Set up next to me, Tommy and Robin sounded as if they were not getting far with their new C8. I had advised them to try SkyAlign, which allows the scope to be aligned on any three bright objects. You don’t even need to know their names. Unfortunately, the NexStar HC kept saying “alignment failure.” While I wanted them to get comfortable with their new SCT, I also wanted to make sure it was working right and make sure they got to see some cool stuff, so I took the controls.

SkyAlign is accurate—I’ve tried it with Big Bertha—but it is pickier about star choices than you might think. I didn’t want to spend a lot of time figuring out which three stars SkyAlign might like, so I did what I consider the most accurate type of go-to alignment for these scopes: “Auto Two-Star.” This mode has you manually slew to the first alignment star; the scope slews to the second one and you are done. Let’s see, the C8 wanted “Albireo” first. Mashed the buttons to move the scope that away, centered the star, and the NexStar chose the second star (forget which) and slewed to it. I centered the sparkler up. “Align Success.”

I took a look and there was globular M3 looking sweet. The optics on the scope were nice, I thought, real nice. I showed Tommy and Robin a couple more pretties, demonstrated how to go to some on their own, and advised the couple to do a little studying of a star chart so they can use Auto Two-Star, too.

Onward to the Big E., then. I started out in Boötes, got in the groove and was soon knocking them out one after another. I’d peer at the Herschel Project list on SkyTools RealTime to see what was “next” and punch it into the virtual HC. When the slew stopped, I’d center the object (mostly wee galaxies on this eve) on the monitor with the gamepad if necessary, hit record on the DVD to grab 30 seconds of video, write the ID number in my observing notebook, record my impressions on my MP3 recorder, and repeat as needed.

What stands out amongst the night’s haul? Boötes is not a place for spectacle. It has plenty of DSOs, but they are mostly small rather bland galaxies. Nevertheless, there are a few you might want to visit, even if you are not a Herschel fanatic.

The Herschel 2500

NGC 5851 and 5852 (H.III.886 and H.III.887). There are three prominent galaxies here, the two NGCs and MCG 2-38-43. NGC 5851 is a magnitude 14.04 S type lenticular that is 1’x.3’ in size and intermediate in inclination. NGC 5852, also an S type, is a little dimmer at mag 14.53 and about the same size, 1.1’x.6’. MCG 2-38-43 shows up very well since, while it is at magnitude 15.3, this little Sc extends a mere .6’x.2’.

This group is a real treat. Three small ones near a bright magnitude 10.67 field star. It’s hard to make out too much about these tiny sprites. NGC 5851 has a bright round core and a rather extensive outer envelope that almost looks edge-on despite its “intermediate” classification. NGC 5852 is also an intermediate, but shows a less skinny disk, seeming round at times. The MCG is easy to detect, but is just an elongated smudge.

NGC 5669 (H.II.79) is an intermediate inclination barred spiral, an SAB(rs)cd of magnitude 12.03, with a size of 4’x2.8’.

This is a big, beautiful galaxy as Herschel 2500 galaxies in Boötes go. I don’t see a stellar nucleus, just a milky bar and two wrapping spiral arms that occasionally swim into existence as the seeing shifts.

Once I got going good it was damn the skeeters, full speed ahead. When I hit object number 35, I felt like I was just getting started, and it was only about 11:30 p.m. There’d be plenty of time to make the 50 object mark, my usual goal for an evening at the club site. I had just grabbed a sequence of M13—you know I will look at M13 whenever it is above the horizon—and was fixing to punch in a “serious” object when the image on the monitor died. What the frack?

I have a horror of my Stellacam II dying. As I’ve mentioned before, it is long obsolete, the original vendor, Adirondack Video Astronomy, is now out of business, and I am not sure I’d be able to get it repaired. There is a new outfit, Cosmologic Systems that is, I believe, selling the Stellacam III, but I don’t know if they could do anything for a II. Looks like it will be next year at the earliest before I am ready to buy a Mallincam, and I would really, really hate being without video for long.

Opening my eyes and ears showed the problem was not with the Stellacam. The time display had disappeared from the DVD recorder, and the inverter was beeping its “LOW VOLTAGE” warning. I’d been afraid of this. After about five years of use, my trolling motor (deep cycle marine) battery just doesn’t have much get up and go left. I should have bought a new, higher capacity one before now; I was lucky to have got two hours out of it. At least I’d been smart enough to swap disks after 25 Herschels. If the dying battery had trashed the one in the recorder, I’d only have lost 10 targets.

What now? I figgered I’d disconnect and stow the video gear and see what the clock said when I was done. What it said was “still kinda early,” a few minutes before twelve. Time enough to take a look at little comet Garradd, which was riding high in Pegasus not far from M15. To that end, I replaced the Meade f/3.3 reducer with an f/6.3 Celestron reducer/corrector, screwed a visual back onto Celeste’s (ahem) rear end, inserted a diagonal, and popped in my trusty 20mm Orion Expanse eyepiece.

Had to get there, of course. I had the coordinates printed out, and it was easy to input them into NexRemote via the “go-to RA/Dec” function of the HC (you can do the same with a non-virtual HC). Keyed ‘em in, punched the go button, Celeste’s CG5 made those weird sounds, and, when she stopped, I put eye to ocular.

There it was. Cute little feller. At first glance, it was a small oval fuzzy 5 – 6 minutes across its longest axis. A little staring and not only did I occasionally glimpse a tiny nucleus, I thought I was seeing signs of a small tail. Curiously, the comet didn’t look much better in a nearby 15-inch Dobsonian than it had in the C8. I expected, from what I’d read, for the comet to be about magnitude 9, but I estimated it to be closer to 8. Who knows? Maybe it will do better than “6” in March when it will be at its height.

And then? I looked at a Messier or two including M15, but thought they looked a little subdued. Why? Shining my red light on the scope’s corrector plate told the tale. It was beginning to fog despite my fairly high setting of the DewBuster. I cranked up to “12” (degrees above ambient) and the lens cleared fairly quickly, but by then it was getting on to 1 a.m. and I thought it was about time to pull the Big Switch. I’d packed the video gear, but there was still a fair amount to do and a 45-minute drive home.

Back at the Old Manse, I reflected on the evening. The star of the show was the CG5. After seven years it still amazes me. Its go-tos are just faultless. Easily as good as Big Bertha’s. Its tracking is sweet, too, more than accurate enough for video. Yes, it makes some weird noises when it is slewing at full speed, but those sounds have become music to my ears.

Oh, the disk that was in the recorder when the battery died? I didn’t dare fool with it when I got home. It was late and I was afraid I might do something dumb, even before I imbibed any Yell. Next morning I fired up the recorder and monitor. The recorder immediately threw up a message window asking me whether I wanted to “recover title?” I said “yes,” it spun for a while, said it was done, and I was able to finalize the disk. Yanked it out, slammed it into the PC, and it worked fine. Whew!

Final tally? Two needed Herschel 400 objects and thirty Big Enchilada aitches. Not bad for an evening when I had to struggle to convince myself to load up a ton of gear and head for the dark site. I can’t promise I’ll always have the gumption to defy heat, humidity, clouds, and bugs, but I’m glad I did this time.

If y’all would like to see my Herschel Project Update video live from the PSAS observing field, go here.

Next Time: Which Kitty?

Comments:
Very interresting as usual.


I would like to ask you a question.
What will be the difference (quality) between an unprocessed CCD camera picture and the stellacam or mallincam pictures ???
 
Unprocessed? Probably more alike than different.
 
I really enjoyed reading this. Nothing like deep sky diving with a great list of objects.

I'm tackling the book "Cosmic Challenge" By Phil Harrington right now.
 
Super! Phil's book is a great one...and I say that not because I helped out on it (a very little bit)...but because it really is one of the greatest observing books to come down the pike in a long time. Enjoy!
 
you have that right Rod!
Glad to be back into observing again and I am blogging about it, love it.


http://thenightskyobserver.blogspot.com/
 
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