by Robert Leyland
The weather this year is proving to be very fickle, beautiful in the morning, cloudy in the afternoon. One of the main trials of this astronomy hobby seems to be finding good weather.
I pulled into Lone Rock flat at Lake Sonoma, around 6pm, to find Matt Marcus already setup, with his TV Ranger and Solar filter viewing some pretty neat sunspots. A lovely group at the equator really caught my eye, a strong leading spot and an inverted-V shaped trailing group.
Sadly, there was a lot of high horsetail clouds. I delayed setting up, but was still hopeful, as in the past these clouds have tended to disperse, leaving clear skies, and soft views.
By 7pm a goodly gaggle had accumulated, and while the clouds didn't look much better they were thinning slightly. I figured it would be a lightweight night for observing, and mentally crossed off those galaxies at the N end of GEM I wanted to catch. I didn't even open my log until almost 10pm.
As the sunset the clouds started to disappear, but the wind picked up. It would bother us intermittently through the evening, and with the overall softness of seeing most folks left early.
| Observer | Robert Leyland |
|---|---|
| Date | 13 Apr 2002 |
| Time | 2000-0100 PDT (UT -7, or 0300-0080 14 Apr 2002 UT) |
| Location | Lake Sonoma CA, 38°43'N 123°02'W Elev ~1500 (Lone Rock Flat) |
| Weather | 19°C dropping to 15°C Temp, 70% rising to 90+% Humidity |
| Seeing | LM 5.5, transparency 6/10, steadiness 7/10, sporadic gusts |
| Moon | just past new moon (1.5 days) |
| Equipment | 17.5" F5 Dob, 5" Newtonian, 9x50 finder scope, Pentax XL EPs |
Since seeing was pretty bad, I didn't start logging objects until late. Early in the evening we shared views with a number of newcomers to the site, and grabbed eye-candy photons from bright Ms, and we checked out the super nova in NGC 3190, which has become dimmer in just the past week. Early evening was taken up by M65/66, M51 (lots of oohs and aahs for the big scope view), later when Corvus cleared the clouds M104, and very late M13, as Hercules rose in the north east.
As the seeing was unsettled, it made sense to go from constellation to constellation, looking for the darkest, most clear region of the sky. Even so a few new (to me) objects grabbed my attention.
In Gemini, NGC 2420 a nice concentrated open cluster at 100x occupied a good chunk of the FOV, easily distinguished from the background, and showed up well in the 5" too. Easy to find by projecting a line from Pollux past Kappa (a double, outside on the left), about the same distance, and then go less than 1° towards Delta.
M101 in UMa showed some spiral structure evening with poor seeing, as lumpiness in the halo. In the 5" the galaxy was obvious, and extended, in the 17" the core and arms came to life.
After hitting M104 in Corvus, Kevin suggested the Antenna galaxies (also known as the Ring Tailed Galaxy, NGC 4038-39.), which I had not viewed before. His star hopping instructions were excellent, as I acted as the GOTO, and placed the object dead center, from the Telrad view (project a line from Delta to Gamma, and go about the same distance beyond Gamma, look about 1° N of a 5th magnitude star). A distinct V of darkness divides the galaxies, which looked like a pair of irregular commas. Very nice view, and I feel for the people living in the heart of the galactic collision, it must be spectacular but very dangerous.
Next to M13, about (0.8 degrees away) is the galaxy NGC 6207, which is a nice elongated oval, with two field stars at an angle adjacent to it, and another dimmer star off the end towards M13. There really should to be a list of overlooked objects, labelled "next to big bright things", as this would surely rank highly on it.
Back in Gemini I looked for NGC 2371/72 a planetary nebula, which has earned two NGC numbers. Directly below Castor, and adjacent to a bright triangle of field stars. This PN is quite bright in the 17" at 100x, it looks circular, but with much brighter "poles" on an axis. At 210x with an OIII filter it really looked like a smaller version of the Dumbell Nebula, very pretty. I suppose that each lobe could have its own NGC number.
Keeping to the PN theme, the Eskimo nebula was next up. It was getting a bit low, but still easy to find star hopping from Delta GEM. It has an interesting double layer structure at 100x, and is really quite pretty even at low power. The OIII filter showed the double layer structure well, but the view wasn't as pleasant, although it does take magnification quite well showing more details at 160x.
After sharing the Eskimo, and keeping in theme, we hopped over to UMa for a spell on the owl nebula M97. I could see the eyes, as darker areas in the disc with averted vision, but the best view came at about 160x with a UHC filter, where the eyes were easy with direct vision. The owl looked good in the 5" too, and was bright enough to handle a filter in this scope too.
One last planetary nebula, as it was getting late. In Hercules, NGC 6210, is totally cool. It is traffic light green; not gray with a hint of green, not white with a greenish tint; but solid chromatically clear, press the accelerator, green. At 100x you can see a little oblateness, in the form of a bulge on one side. An OIII filter, and higher power (210x), knocks out the central star somewhat, and makes the shape more obvious, but loses some of the color.