by Robert Leyland
The last couple of weekends have been a bust, and aside from a couple of school star parties I hadn't had any good observing time. One session at home with an 8" Dob, was marginal, just logging a few open clusters in CMa, and Gem.
So on Monday, with crystal clear skies all day, I left work a little early, and drove up to Lake Sonoma. I was late getting started, but luckily this meant that i missed all the traffic problems, usually associated with the evening commute.
| Observer | Robert Leyland |
|---|---|
| Date | 18 Mar 2002 |
| Time | 2000-2300 PST (UT -8, or 0200-0500 19 Mar 2002 UT) |
| Location | Lake Sonoma CA, 38°43'N 123°02'W Elev ~1500 (Lone Rock Flat) |
| Weather | 8°C Temp, 55% Humidity |
| Seeing | LM 6.0+, transparency 9/10, steadiness 7/10, intermittent strong breezes |
| Moon | early first quarter (5 days) |
| Equipment | 17.5" F5 Dob, 5" Newtonian, 9x50 finder scope, Pentax XL EPs |
Driving up, as darkness fell, I got a good view of Venus, very bright in the twilight. I arrived at Lone Rock flat after sunset, with just a touch of twilight left, perhaps it was zodiacal light.
Just getting out of the car, scanning the western horizon, Comet Ikeya-Zhang was prominent. This is a BRIGHT comet, easy naked eye tail, and star like nucleus, brighter than any of the stars in Pisces.
I studied it in 15x70 binoculars, following the tail up until I could no longer discern any change in brightness. There are clear streaks in the distinctly blue tail, and a coma about the head of the comet is obvious even in binoculars. I couldn't detect any movement, as was possible with LINEAR 1999/S4 a year or so ago, especially since there weren't any convenient field stars to detect movement against.
I hurriedly setup the 17.5", with newly attached 5" finder. Without taking the time to collimate, or really get the finders aligned, I just had to view the comet. It is remarkably easy to find simply by sweeping the view horizontally, and looking for the brightening tail, then following that down to the head, Simply awesome.
In the big scope, the tail is much better differentiated, and sweeps far higher into Pisces, perhaps as much as 5 degrees. The head has a semblance of a disk, but no shape other than circular, with gaseous emission surrounding it far larger than its own diameter.
By this time the comet was pretty low, but I was a bit lucky, as I had setup in the center of the lot, and the comet was setting between two trees on the western horizon, so I was able to follow it for longer than I would usually have been able.
It finally set around 9pm, and I got around to collimating and lining up the finderscopes. I've added a short tube Newtonian to the base of the Dob, to provide better widefield views, and to see a little deeper than the 9x50 RA finder. Some objects just look better at low power, and 5" is enough aperture to see brighter galaxies, and to get a good handle on most open clusters.
Starting at Gamma Leporis, a pretty double star in its own right, a short star hop brings up NGC 2139, which is tough to see in the moonlight. Solitary stars above and below match the sketch in NSOG, and the galaxy core is visible with direct vision, but the halo only with averted vision.
NGC 2196 is a small circular galaxy with what seems to be a linear brightness curve from the center peak out through the halo.
NGC 2179 Galaxy, shows as just a strip of fuzziness, close enough to a bright star that I need to maneuver it out of the FOV in order to clearly see the galaxy. It is obviously elongated, but averted vision, and a little movement helped to bring the shape out.
This wraps up my first survey of Lepus, covering the deep sky objects down to 13th magnitude, which is a good time to finish, as Lepus is getting much more difficult to observe!
Starting easy, with M41, which is noticeable in the 9x50, but really shines in the 5", it is one of those objects that is better in the smaller scope.
I spent some time trying for NGC 2283 (Galaxy) with no luck, the moon, inexperience, worsening sky conditions, I believe I should have been able to see it, and had the location well matched with charts. Next time I guess.
Nasty breezes had been pushing the telescope around quite a bit, and had brought some light cloud in across the west and south horizons, so I spent the remainder of the evening hitting bright Ms and trying out the new "finder" on such delectables and M104, M51, M65/66 and M60. All easy fodder, and good reminders of why its worth driving an hour each way for three hours of observing ;-)