Dino, 11/3-4/2007: yet another DIno OR 3 Nov 2007

Matthew Marcus

The comet was naturally the big sensation. I can't add much to what's already been said except to say that the greenish outer halo really seemed to be real, showing up in a very consistent way in a wide variety of binos and scopes. In the bigger scopes, it was necessary to put the comet off the field in order to see the halo. While the small-optics view suggested a fairly sharp boundary to the halo, the larger scopes showed it to be gradual. In any case, I think most observers agreed with me that the halo was green and tripled the diameter of the comet when viewed through small optics. When I showed my sketch to some others, they noted that the halo wasn't included, so I figured out a new method for putting in diffuse stuff like that: I make a heavy pencil smear on another part of the paper, rub my finger into it, then run the finger around where I want the halo to be. Unfortunately, light markings like that don't show well under red light, so when I got the sketch under white light, I found that the halo was nearly as intense as the disk. Oops! Think of it as a sort of contrast-stretching; I not only image with pencil&paper, I over-process with pencil&paper as well :-)

In a mooched view at 380x, I'm pretty sure I saw something that I don't recall being mentioned: the nearly-stellar pseudonucleus had a light side and a dark side, much like the spacecraft pix of Halley's nucleus. This required more aperture (15") than my 8" to see, so I couldn't confirm with my own scope.

The seeing was quite good for most of the night. Although Mars is still small and was fairly low when I looked, I could see considerable detail. No polar cap, but several dark markings at 250x using an Hbeta filter as a color filter (my usual planet trick, exploiting the 'extra' red passband). Stars showed broken but visible diffraction rings. Late in the evening, I tried for the Pup, but the seeing had gone.

As I was breaking down, I saw something red come up over the dam. I couldn't quite resolve it in an 8x finder (what I had available at the time), but the Last Man Standing (not me, for a change!) put his scope on it after it had risen a while and turned whiter, and saw a white half-moon, so the mystery object was duly identified as Venus. I'd never seen a red Venus before, but it makes sense that if the sun could rise red, Venus would as well. What threw me is how long the red color lasted.

Though many people thought the sky was darker than Coe (not saying much these days, sigh!) or FP, I though it didn't quite seem to be all there. The Miky Way seemed washed out (the Skim-Milky Way?) and I was having trouble pulling out 12th-mag galaxies which should have been relatively easy. Later on, when Orion was nearly on the meridian, I tried for the Horsehead and didn't succeed. I really hope that these problems arose from the sky and not my eyes!

Aside from the above, and lots of standing around chatting, I worked a bunch of deep-South objects. Dino has one of the better Souths of our usual observing sites. Lake Sonoma goes deeper in its notch, but Santa Rosa pollutes a large part of the Southern sky. Anyway, since Sculptor, and later, Fornax were set to transit the meridian, it was galaxy season, and a continuation of the sweep of Sculptor I was working on at Lake Sonoma last month. I also did a bunch in Cetus, though I never did get around to M77, our neighborhood Seyfert. The objects I logged:

227, 245,337,450 (Cetus)
274+275 (Cetus, near-contact pair of galaxies)

1344,1351 (Fornax)

1374, 1375, 1379,1381,1387,1389,1396(number from memory), 1404 (Fornax I group)

I also went for 1365, hoping to see the 'Mark of Zorro' shape, but the sky was just too murky and I only got the central part of the bar, which I had already logged from Lake Sonoma. It may require more than 8" to get the full image from Bay Area skies.

My last logged object was Cederblad 90, a patch of reflection+emission nebulosity in CMa, at the end of a faint (too faint for me to see) nebula complex which is degrees long. After logging that, I did some eye candy, did the dance with Venus described above, and went home.

mam