by Robert Leyland
A second weekend, in a row, of very good observing conditions. This weekend was, if anything, better than last with similar transparency, and improved steadiness. It bodes well for the rest of the summer.
We had an unusual collision of interests at Lake Sonoma, as our usual site had been reserved by a group for some ritual of a religious nature. A small number of folks, wearing flowers and ribbons, were using the hilltop adjacent to Lone rock flat for a late/over night event. A classic California culture clash.
They seemed nice folks though, and were quite willing to redirect late comers back down to Grey Pine flat, which is about 400 feet lower, and has slightly more restricted horizons.
As I had arrived early, I got to spend a bit more time setting up, and getting the balance right on my Dob. I recently mounted a bracket from Ken's Rings http://users.kricket.net/ken/rings.htm, and had been trying out an Orion 130ST Newtonian as a "super" finder, and wide field telescope in tandem with the main 'scope. However the off axis weight created some balance problems; both near zenith, and near the horizon. I was able to resolve this by using some wraparound ankle weights: one under the mirror box velcroed around the H mirror support, which provides balance near the horizon; and the other on the front handle of the box which which provide the off axis balance needed near for observing near zenith. After a bit of fiddling, including sliding the little Newtonian all the way forward in the rings, I was very happy with the result, and during the course of the evening I only had one instance where the telescope shifted through imbalance. Generally it stayed pointed where I left it, the motions remained smooth and easy, despite the added weight.
About a dozen of us gathered on the NE end of the lot overlooking the lake, which provides great background scenery during the late afternoon and twilight, and set up 8+ telescopes. Some of the regulars were absent, but we had several newcomers to the site and all enjoyed themselves.
| Observer | Robert Leyland |
|---|---|
| Date | 11 May 2002 |
| Time | 2130-0030 PDT (UT -7, or 0430-0730 5 May 2002 UT) |
| Location | Lake Sonoma CA, 38°43'N 123°02'W Elev ~900 (Grey Pine Flat) |
| Weather | 21°C - 12°C Temp, 40% falling to 33% Humidity |
| Seeing | LM 6+, transparency 9/10, steadiness 8/10, sporadic breezes |
| Moon | new moon |
| Equipment | 17.5" F5 Dob, 5" Newtonian, 9x50 finder scope, Pentax XL EPs |
We caught the planets setting in the dusk, and comet Ikeya-Zhang later in Hercules. The comet showed no tail per se, but rather an asymmetric shape with the head closer to one side of the coma, a little like a bow shock. This was easiest to see in the 5", while the 17 gave a great close-up view of the head. One observer had a Sky 90 with a wide field eyepiece and lined up M92 and the comet in the same FOV, some 6.5° separation at about 12x magnification, he jokingly referred to his Pentax 14 as the "narrow field" eyepiece as it was only 2° wide.
Last week I had made good progress in Corvus, and my plan was to try to do the same in Crater which I had skipped over accidently. Perhaps others have done this too, as I don't see many reports mentioning the Cup, and yet there are some nice galaxies just waiting.
I followed the finder charts in NSOG, finding most objects listed in an intense and focused observing session.
NGC 3571 a nice little oval galaxy by Psi CRT centrally located in the base of the wine goblet. The core is mildly elongated, about 2:1. At 160x the bright star Psi can be placed out of view, which makes studying the galaxy a little easier.
IC2627 off Beta CRT, is a diffuse mostly circular area, perhaps 6:5 ratio oval. Averted vision shows a hint of a core at 100x, but this fades at higher magnification.
Not far from IC2627, but a little further from Beta, is a nice pair of galaxies NGC 3511 & 3513. This close pair consists of an elongated oval (3511) about 5:1, possibly edge on, and a flatter oval, about 3:1 oriented 60° away.
Pushing further out, towards Hydrus, brought up NGC 3464 which is a modest sized, faint, oval galaxy.
Triangulating from Alpha CRT and Nu HYD is a small, faint circular galaxy (NGC 3456), with an adjacent field star, and bracketed dimly by another star in the galaxy's halo.
Moving up to the top of the cup is galaxy NGC 3732, it appears small, with a concentrated core. It is a relatively easy find being approximately 1/5th of the way between Upsilon and Epsilon CRT.
The next pair of galaxies gets the prize for being the easiest find of the night. Hop from epsilon to the next bright star out from the cup, and the two galaxies bracket this star. Both are small ovals, that form an L shape with the much brighter star. Each galaxy contains a small core, with 3637 slightly larger and more elongated.
>From here I stepped back towards 4732, stopping next to a pair of stars that point to NGC 3672. this interesting galaxy is elongated
Moving outward from the cup brings up NGC 3660, which is another small, circular and faint galaxy, with a hint of a core. It is a relatively easy find midway between a pair of bright field stars (6th mag). A nice asterism or 3 or 4 stars to the side of the galaxy sets it off from the background.
After a small break, I returned to the top of the cup, projecting off Upsilon to an easy T shaped asterism, projecting off the cross bar of the T is NGC 3865, yet another small circular galaxy. This one has a stellar core, visible with averted vision at 160x.
Moving across the top of the cup, brought up NGC 3892 a dim oval with a small core that was easier seen with averted vision. A nice arc of 5 or 6 stars lead right to the galaxy, with one faint star adjacent having the same brightness as the core.
Continuing in the same line, across the cup I found NGC 3962, which is small with a stellar core and looked to have a somewhat mottled halo, however higher power didn't resolve this. a pair of field stars next to the galaxy allow me to find it in the 5" and hold it with direct vision as a somewhat fuzzy point.
A very good night, 14 new objects, excellent viewing and good company. I packed up a little earlier than I would normally, for Mothers' Day, and finished up with a few eye candy objects.
These included the Leo triplet, with the dark lane in MGC 3628 prominent; M104 the Sombrero, with the "lower" part of the galaxy forming the chin under the hat brim; M13 in Dick Flasck's 17, in which we could see a small knot right at the very core of the globular, trés cool.