Sunday, February 17, 2013
The Early Return of Comet Kahoutek?
Those of you old enough to remember Comet Kahoutek’s much heralded but poor showing back in ’73 probably know where I am going with this. I am not, repeat, NOT talking about Comet PanSTARRS (C/2011 L4), which will emerge from the Sun’s glare next month. That is probably a done deal already, I am sorry to say. If you ain’t heard, PanSTARRS is indeed pulling a dadgum Kahoutek at this very moment—not living up to its billing or even coming close.
Brightness estimates for PanSTARRS have been revised downward, with it now expected to peak at about magnitude 3.0. For you greenhorns, Polaris, the North Star, is brighter at 2.0, and the comet, being an extended object, not a pinpoint, will look considerably dimmer than a one-magnitude difference would suggest. In other words: nice binocular object from dark site, but nothing that is gonna get my old Aunt Lulu or the public stirred up. Don’t fret, though; there is a potential goodie on the way in, C/2012 S1 ISON, if it doesn’t go down the Kahoutek path too.
David Levy has often compared comets to cats. Not only do they have tails, they tend to do exactly the opposite of what we expect or want them to do. And PanSTARRS was enough like Kahoutek to make my alarm bells go off: a virgin comet (given the hyperbolic shape of its orbit) that brightened early and could turn spectacular when it hit the inner Solar System if its brightness continued to increase. Problem is, comets don’t tend to put on spectacular shows on their initial visits. They usually tease, with a thin layer of volatiles boiling off early and making them look “Great” when they are on their way in, but the hard frozen stuff below barely fizzling when they get closer.
Unlike PanSTARRS, ISON has at least the potential for being a Great Comet. It MAY not be a virgin. It may, in fact, be a piece that broke off The Great Comet of 1860. It’s already surprisingly bright—a little dimmer than magnitude 14—given that it’s farther out than Jupiter’s orbit. The geometry is also right for it to put on one hell of a show for the Northern Hemisphere in December and January. That’s, of course, just the time back in 1973 that Kahoutek was supposed to strut her stuff, so be cautious; especially when dealing with the public. Kahoutek was a bigger disaster (in the public’s reckoning) for astronomy than even the pitiful Halley.
Still, Unk doesn’t mind saying he is hopeful about this one. Considerably more hopeful and less cautious than he usually is about comets at this stage of the game. It may even turn out to be Ikeya-Seki II, not Kahoutek II. When did Unk stop being a comet curmudgeon? Saturday night a week ago.
That Saturday was the evening for one of Unk’s dark of the Moon runs from the Possum Swamp Astronomical Society’s vaunted Dark Site. What I was supposed to be after was mostly Herschels; in fact, it was to be Night Thirty-Seven of the Herschel Project. “Night thirty-seven, Unk? We thought you was done with The Project and on to something called ‘The Herschel Project Phase II.’” I decided that sounded silly. While I’ve observed all the Herschel objects and am now just going back and re-imaging/sketching a limited number of them, they are still Herschels and I am observing them, so it is just The Herschel Project from here on out.
Anyhoo, before loading up the 4Runner, Miss Van Pelt, I sat down to SkyTools 3 and had a look-see about what was what—what would be up and well placed. I intended to go after the spring crew, Ursa Major, Virgo, and Leo, who would begin to climb out of the Possum Swamp light dome at mid-evening. What would I do till then?
When I’m preparing for a run, I always check ST3’s “Current” lists, Current Novae and Supernovae and Current Comets. These observing lists are one of my favorite SkyTools features because they are dynamic. “Huh?” What I mean is that you click “Update ‘Current’ Lists from Web” on the Observing Lists pull-down menu, and SkyTools automatically retrieves new objects, clears old ones from the lists, and updates coordinates as required. The lists of comets and supernovae (there’s “Current Minor Planets,” too, but I ain’t interested in asteroids at the moment) are always, well, “current” and I don’t have to struggle to make them so.
Looked at supernovae first—I am continuing my informal project of imaging the good ones—but nothing caught my eye. Oh, there was one in Leo, but it wouldn’t be up any earlier than the Leo galaxies I was after, and at magnitude 14.7 it would be a little dim down in The Swamp’s light dome.
OK, comets then. While that rascal PanSTARRS was still in the Sun’s glow, our supposed Great Comet, ISON, would be in a good spot. What did SkyTools say about it? Couldn’t get much better placed; it would be in Gemini and nearly at the zenith not long after astronomical twilight. It is still far-far-away, as you can see in the TheSky 6 screen at left, and I knew it would be dim, but SkyTools prediction of “magnitude 14.5” didn’t scare me like it would have in the pre-video days. The Mallincam Xtreme gobbles small objects of this magnitude like salted peanuts.
That took care of the objects then—Herschels and ISON. What about the sky conditions? Did not look good, campers. The weather goobs were divided between “partly cloudy” and “mostly cloudy,” with most of them tending to the latter. I didn’t care. I was going to the dark site if it wasn’t raining, and that was that. It would not be a wasted trip, even if I couldn’t see a dadgum thing. I needed a few terrestrial type pictures for a magazine article I am writing, and I prefer the photogenic PSAS field to my constricted backyard as a background.
Equipment? I was sorely tempted to haul out Big Bertha, the NexStar 11, but in addition to me being just naturally lazy, especially about lugging overweight scopes (sorry Bertha) back into the house in the wee hours, I still have the stitches in from my travails of last week, and I dang sure didn’t want a setback. The C8, Celeste, it would be. I had an agenda concerning her, too. She needed a thorough checkout before the spring observing season.
Actually, her nibs didn’t need a checkout. As I mentioned not long ago, Celeste’s motofocus woes were fixed with the assistance of JMI and she was ready to rock. What did need testing was the CG5 mount she rides on, and, specifically, the mount’s interface with the NexRemote computer program.
Last time I’d used NR with the mount, I’d had “No Response” messages on the hand control all night long, communications errors out the ying-yang, that is. I believed the problem was a bad RJ connector on the Celestron Auxiliary Port Accessory that adds a PC port (different from the serial port on the hand control) to the CG5 so I can run NexRemote without the real, physical HC being present. I’d crimped a new connector onto the Aux Port Accessory’s cable, and while I was pretty sure that fixed the problem, my schedule and the weather of the last six months had seen to it that I had not been able to test the mount with NexRemote.
It’s Mardi Gras, y’all…which is cool. Ol’ Unk has been known to do a little Fat Tuesday partying himself, but the traffic is hell. Because of that, and because of the aforementioned terrestrial pictures I needed to take, I pointed the 4Runner west at 3:45 p.m. That would give me a good hour before sundown for set up and picture taking. The sky? It didn’t look good at home and it didn’t look good when I arrived at the PSAS site. Not horrible, but plenty of high clouds, high humidity, and the blooming jet contrails that spell “bad weather a-coming.” That was OK. If I just got the photos for my article it wouldn’t be a wasted trip.
I had my choice of observing positions, that was for dadgum sure, since there was nobody else on the field and I didn’t expect there to be. There was still some blue, but the clear patches were shrinking, and I figgered my observing buddies would be at the parades—one of the biggies, The Mystics of Time with their famous Vernadean (pronounced "Verna Dean," you-all) the fire-breathing dragon, would be rolling. The PSAS site is our little patch of dark sky heaven on new Moon weekends, but the rest of the time it is an airfield. I set up just down from the big hangar in hopes of not getting spookified as I sometimes do when I am alone and on the far end of the observing field.
Not that I was much worried about that. I didn’t have the slightly jittery feeling that presages “visits” from The Skunk Ape, Mothman, and The Little Grey Dudes from Zeta Reticuli II. I might feel entirely different later, of course, but it looked like I’d have plenty of company this evening. The Coast Guard Auxiliary was having a big cookout at the hangar, and the presence of even one other person always wards off my strange friends.
First order of bidness was getting the CG5 tripod set up, the mount head on that tripod, and Celeste on the mount so I could take my pictures with the Canon DSLR. I had hit what photographers call “the golden hour,” and got some photos I liked. Terrestrial shots in the can, I proceeded to get the copious support gear hooked up and running. I admit I did briefly consider just loading scope back in the truck and turning Miss Van Pelt for Chaos Manor South, but, man alive, it was barely 5:30.
What all do I gotta do to get ready to image the sky with a video camera? First thing is put the reducer on the telescope. Deep sky video camera chips work their magic by being small and having large pixels. That makes them quick to refresh and sensitive. The downside is you ain’t gonna see much if you don’t have a wide-field telescope. Luckily, an SCT can be a wide field with the addition of a reducer. What I’ve used for years is a Meade f/3.3, which screws onto the rear cell just like a Celestron f/6.3 reducer/corrector. A William Optics 2-inch visual back with a 1.25-inch adapter goes on that, and the Xtreme with its 1.25-inch nosepiece is inserted into the adapter.
That’s just the start, friends. A Video cable runs from the camera to the switchbox that distributes video to either my Orion mini DVR or to the portable DVD player I use as a monitor. There’s a serial cable for camera control, and that goes into a USB - serial adapter on the netbook. Gotta have power for the camera, natch. I always run my Xtreme from a jumpstart battery pack; I’ve found DC from a battery results in the cleanest video.
Then there’s the scope/mount stuff. There’s no hand control; instead, the NexRemote cable goes from a second USB – serial adapter on the netbook to the PC port on the Celestron Auxiliary Port Accessory, which is connected to the hand control port on the mount. A JMI motofocus goes on Celeste’s focuser, and a long extension cable runs from it to the motofocus control stationed by the monitor. The mount’s power cable (a short, coiled one from Scopestuff.com) is plugged into a multi-outlet adapter connected to a second jumpstart battery, which also powers the DewBuster heaters.
Whew! Not quite done yet. I need a 12-volt battery to power the DVD player, so I use a jump starter with two cigarette lighter receptacles. One is for the DVD player’s DC cord, and the other one, via an inverter, electrifies the netbook’s AC power supply. The netbook would probably last all night on its internal battery, but the 12-volt battery ensures I’ve always got more than enough amps to keep the PC going. Same goes for the DVD player: I could run it off its internal battery, but I don’t want no power failures just when I’m about to capture the long-sought UGC Umptysquat. Once I was done with all the astro-junk, the sun was well down, and it was time to see something—maybe.
The sky looked worse than ever, but I could nevertheless see plenty of alignment star candidates in the gloaming, and I’d be able to give the mount a good test just by running through its alignments. Turned on the camera, overlaid a set of Xtreme-generated crosshairs on the screen, set the exposure to a couple of seconds, and launched NexRemote. “Celeste” (actually the netbook’s Microsoft Mary voice) instructed me to “Select settings and press enter,” loaded the site’s location, which I’d stored on this computer via NexGPS a long time ago, got time and date from the netbook, and we were off on a two-star alignment.
First star? “Mirfak,” Celeste said. “Where in the H-E double L is ‘Mirfak’,” Unk replied. Oh, yeah, in Perseus. I’ve never been much good at star names once you get off the beaten path of Sirius and Betelgeuse. Centered Mirfak, did the same for Celeste’s second pick, Hamal, and it was time to—yes—do four more stars.
The go-to accuracy of the CG5 is amazing. It is as good as, or usually better than, my NexStar 11. The main reason for that accuracy is that it uses four “calibration” stars in addition to the two stars used for the pointing model. The calibration stars allow NexRemote (or the hardware HC) to take various mount misalignments into account. The next to the last cal star was in the field when the mount stopped, and number four, Capella, was centered without me having to do anything.
Aligning on four stars took all of 10 minutes, but the mount’s alignments were still not done, not even half done. If you want to expose for more than a few seconds, you need a decent—though not perfect—polar alignment. I do that with the hand control, but not with Celestron’s new(er) AllStar routine. I select one of the earlier CG5 firmware builds, v4.12, in NexRemote, one that has the older Polaris polar alignment, which I prefer. The mount points to where Polaris should be given a good polar alignment and you tweak the GEM’s altitude and azimuth adjusters till the star is centered. I got Polaris smack in the middle of the Mallincam crosshairs.
Alas, to do that, I had to move the mount a fair distance in altitude and azimuth, which would have thrown the go-tos off. So…another alignment with six stars. Some folks say you can stop adding calibration stars once one is in the field at the end of a slew, but that’s usually star three, so I just go ahead and re-do all four. Once I get into the alignment groove, it ain’t that big a deal to do a dozen stars. Using a Logitech Wireless Wingman gamepad as my hand control, as NexRemote lets me to do, makes it duck fracking soup. How else you gonna occupy yourself before it gets good and dark, anyway?
Going to twelve stars allowed me to thoroughly check the CG5 if nothing else. I didn’t get a single No Response error, and there were no crazy or inaccurate slews to alignment or calibration stars. All was as it should be. ‘Course, Unk is of the “trust but verify” school of thought, so I did a couple of test objects, punching “M79” and “M35” into the virtual HC. Both DSOs wound up well-centered. Cool!
Only one more thing to try. Last time I’d used NexRemote’s Virtual Port with the netbook, it had made the NexStar 11 act crazy. The virtual port feature, which allows you to use an external computer program like SkyTools or Cartes du Ciel in conjunction with NexRemote, had been all messed up. Bad go-tos, bad tracking. I suspected the problem was either a faulty USB - serial adapter or an outdated version of NexRemote. I bought a new Keyspan USB - serial adapter and I updated NexRemote both on the netbook and on my Toshiba laptop. The virtual port worked perfectly on the laptop down Chiefland way last month; we’d see how it would do with the cotton-picking netbook on this night.
I launched SkyTools 3 and connected it—with ASCOM—to the virtual port, com 6, I’d chosen during NexRemote’s setup. The netbook let out a reassuring bing-bong, and it was time for another test object. How about M42? Hard to miss that sucker, even in the constantly building haze. Highlighted it on SkyTools Messier list, mashed ST3’s “slew to” button, and the Great Nebula landed dead center on the video screen. OK, how ‘bout the other side of the sky, to NGC 457 in Cassiopeia, the E.T. cluster? Smack in the middle. Tracking was excellent too. Unk was overjoyed, since the virtual port would make hunting comet ISON a lot easier. No need to manually input the visitor’s R.A. and declination, just click (in ST3) and go.
OK, comet time I reckoned. ISON was hanging out in the western part of Gemini, which was good and high and relatively free of clouds. Loaded Current Comets, highlighted ISON, pushed the slew button on SkyTools, and the CG5 made her usual weasels with tuberculosis sounds. Not quite loud enough to make the coyotes howl, but almost. That’s just the way it is with a CG5, but it is worth it for the mount’s outstanding performance, and to be honest it’s not that loud. It just seems that way on a quiet field. After the mount stopped, I waited for the Xtreme’s 15-second exposures to catch up, for the stars to become pinpoints again, and had a good look at the screen.
What did I see in the frame? Plenty of stars in this medium rich area, but not a one of them appeared fuzzy enough to be a distant comet. OK, then. More exposure, 28-seconds. Still no cigar. Looking up at the constellation, I could see Gemini was just about due for a good sucker hole. I tweaked focus and cooled my heels.
While waiting for the band of clouds to clear Gemini, I wandered around the site. I was by myself, yeah, but over at the big hangar the Coastie cookout was in full swing, so I wasn’t lonely; I just enjoyed the cool but not cold evening. It was damp, but not crazy damp as it sometimes is this time of year down in The Swamp. The DewBuster was set to “5-degrees” and kept up easily.
When the comet’s area of Gemini was finally in the clear, or what passed for clear on this night, I cranked the camera back up to 28-seconds and had another look-see. “Weeellllll…not really…but…wait... What’s that?” There was a fuzzy and seemingly slightly elongated “star” visible. I brought up SkyTools’ Interactive Atlas and compared my screen to the comet’s plotted position. Once I had the camera-vice-atlas orientation differences figured out, it became clear I was indeed looking at tiny little ISON. In other words, victory!
I recorded several video sequences of the comet at 15 and 28-seconds. I tried 1-minute, but the haze-scattered light pollution made the image’s background an ugly brownish green and 1-minute didn’t reveal any more of the comet than shorter exposures.
What now? I was pumped, let me tell you. Bagging the comet just whetted my appetite. I wanted more of the deep sky, even though conditions were continuing to worsen. A look at the Eskimo Nebula, which was bold and green even in the mess, another visit to the Messier bunch, M79, M35, and M79, and I was done whether I was ready to be or not. The sky closed down completely with a nearly audible thud.
Before shutting down, I strolled over to the hangar to visit with my hosts for a while. They were very kind, urging Unk to try some of the Conecuh sausage—one of my faves—they were grilling. Smelled oh-so-good, but, as above, Unk is still cautious about his poor mouth, and crispy grilled sausage might be a recipe for disaster. I walked back over to the gear before I could give in to my sausage desires and began shutting the rig down.
When you’ve got this much gear on the field it is admittedly a pain to pack at the end of the evening. The secret? Take it easy, work slowly and methodically. Don’t rush and don’t worry about the clock and you will be much happier. I got the computer and the video equipment stowed and stopped to shoot a few more DSLR pix for the article before finishing packing. Driving off the field, the clock in the truck said it was barely past 8:30. That was OK; I’d done the best I could with the sky I’d had and had got some things accomplished.
Back at Chaos Manor South, I had to unload all that gear—with Mardi Gras in full cry, there’s no way I’d have left anything in a vehicle. Anyway, unpacking doesn’t seem like a huge task when I am not faced with getting the 12-inch Dob or the C11 back up the front steps and into the house. By ten I was sampling the Rebel Yell and cable TV.
Sitting there watching as Svengoolie rolled Frankenstein vs. the Wolfman, letting the Yell warm my old bones, I gotta say I was pretty satisfied. To be honest, I’d been worried about my nearly nine-year-old CG5. Oh, I knew it would work OK with the hardware hand control, but I had been concerned about NexRemote. I simply don’t want to give that up and was beginning to think I might have to consider a CG5 replacement, Celestron’s CG5 successor, the VX.
Cheap as Unk is, it was nice to know I wouldn’t have to worry about that for a while, muchachos—though that may turn out to be a short while. The VX/Edge 800 combo shore looks sweet. What was really sweet, though, was getting a look at ISON. If it does become a Great Comet, I’ll have the satisfaction of knowing I saw it as early as I could. Just like I did Hale Bopp, who I captured as a wee fuzzy—if brighter and closer than ISON was on this night—with my Rolleiflex piggybacked on Celeste (on her original non-go-to fork). If ISON works out, this will be Celeste’s second set of Great Comet baby pictures.
Next Time: How Unk Almost Became a Dob Guy…