MB, 4/8/2004: A comet, some widefield views, Omega Cent

by Marek Cichanski


Saturday night turned out to be a really nice night at Montebello...

I had planned on going to Coyote Lake, but when I woke up on the couch at 6:30 after an unscheduled nap, I felt like a rag doll. A big barbecue earlier in the day had not done anything for my wakefulness. I fired up the browser, all set to stand down from my OI, when I saw that David Kingsley had called in the MB permit and was heading up the hill for a short night. That sounded do-able.

I arrived shortly before sunset, and I was pleasantly amazed to find it almost completely calm at MB, despite the wind that we'd had earlier in the day. David arrived shortly thereafter, and Andy Pierce stopped by for an hour or so. I set up my ED80, and later, my M603. David had his AP Traveler and a 7" dob, and Andrew had a short-tube 80 and a C9, which he used to take some digital images of comet NEAT.

After looking at Venus' slender crescent, we naturally turned to the comet. It was still located several degrees southwest of Procyon, and it was very nicely placed in the darkest part of the Montebello sky. I made a sketch of it in the ED80, although I wasn't entirely happy with my rendering of the tail. The tail was fairly prominent, especially at low powers and in binoculars. The most remarkable thing about the comet was its perceptible motion! One could very easily see changes in position (relative to the field stars) over the course of an hour, and with a little work one could see motion in as little as 10 or 20 minutes. Cool!

I continued to play around with the 31 Nagler, looking at wide field views in the ED80. (20x, 4 degree field, very sharp stars to the edge of the field.). The Beehive and M46/47 looked particularly nice. Later, when David noticed that the seeing had gotten fairly good on Jupiter, I put the M603 on the mount and used that for a while. The GRS was getting close to the central meridian and a moon had come out of occultation.

At one point we noticed that the preceding end of Scorpius was rising - summer is nearly here! I looked to the right of Scorpius and wondered "what are all of those bright stars - oh, that's Centaurus!" Suddenly I realized that Omega Centauri might be visible. It was, and very nicely so. We could have seen it even higher if I'd thought about it earlier. The transparency seemed to me to be pretty good near that part of the horizon, as Omega Cent seemed to be very prominent in binoculars, even though it was some way past culmination. At 167x in the 6" M603, I could just begin to make out a few resolved stars in the outer part of the cluster. I wish I'd had my 10" dob.

David packed up and left around midnight. It was a very nice evening of observing and chatting about everything under the sun - er, stars. The breeze picked up a bit, but didn't get objectionable, and I continued observing for a while. I looked at Markarian's Chain in both the M603 and the ED80, using the Terminagler. Had a nice look at M13 in the M603, and resolved more stars in it than I'd ever done in that scope. It seemed to me that the eastern sky wasn't as bright as usual, although I can't explain why - there wasn't much cloud or fog below us.

I also undertook to try to see Omega Centauri with the naked eye. I took my Orion observer's blackout cloth and made a sort of shroud around my face, to admit only the light from that part of the sky. With extensive use of averted vision, I felt fairly confident that I'd seen it. I couldn't hold it, even with averted vision, but I was able to get 'repeatable glimpses'.

The moon rose as I was packing up sometime after 1am, and it was a wonderful moonrise. I watched the moon rise through binoculars. I really enjoy seeing the grass and bushed silhouetted against the disc of the moon. On this particular occasion, I was amazed at the amount of detail that I could see on the moon, while merely using binoculars. (I was using Orion 'Mini Giant' 9x63s.) I could see all of the major maria and some of the smaller ones, such as Sinus Medii and Mare Frigoris. Grimaldi showed up very plainly near the western edge of the moon. the dark patched at the southern edge of Serenitatis were very easy to distinguish. Rays from all of the major craters were easy to distinguish. I could plainly make out Aristarchus, Copernicus, Tycho, Clavius, Plato, Artistoteles, and Eudoxus. Posidonius looked great on the terminator, and I thought I could see the shadow cast by the Rupes Altai. It was by far the best binocular view I've ever had of the moon.

Some fog had started to push through the gaps in the hills, but it didn't get near the observing site by the time I left at 2am. Temperatures on the drive down the hill were around 45-50 F. Some light haze above the Bay Area, but no major valley fog.

If anyone is looking for a nice view of the comet, MB is a pretty nice place to go. I may go back up again tonight, energy level depending.


Posted on sf-bay-tac May 09, 2004 11:21:50 PT
Converted by report.pm 1.1 Jul 11, 2004 14:44:08 PT