Northern California is awash in haze. Dust from Asia we are told, however considering that it all seems to be low altitude, the story is hard to credit. It does make for a pretty sunset, though.
Recent weather has been cloudy, clearing in the afternoons, so after a few phone calls, and some e-mail exchanges, a group of us gathered at Lake Sonoma, for some springtime astronomy. Amongst us we had telescopes ranging from 100mm to 440mm (an AP Traveller to a 17.5" Dob), with an assortment of sizes in between including two 5" SCTs.
| Observer | Robert Leyland |
|---|---|
| Date | 14 Apr 2001 |
| Time | 2000 - 0030 PDT (UT -7, or 0300-0730 15 Apr 2001 UT) |
| Location | Lake Sonoma CA, 38°43'N 123°02'W Elev ~2600 (Lone Rock Flat) |
| Weather | 10°C (falling to 1°C) Temp, 60% (rising to 90%) Humidity |
| Seeing | LM 5.5, transparency 6/10 |
| Equipment | 8" F6 Dob, Telrad + 7x50 finder scope, Pentax XL EPs, NexStar 5 SCT, 15x70 Bear binoculars |
General observing conditions were poor, with hazy skies, particularly near the horizons. This haze was illuminated by lights from the two nearest towns, and increased the size of their light domes considerably. A stiff breeze kept us quite cool, until it died down completely at about 8:30pm, and we all felt much warmer, even though the temperature had dropped 5°C by then!
Overhead the sky was quite clear, and LEO was favourably placed for me to continue tracking down objects from my list. I've used Duane Frybarger's site (Deep Sky Search -- http://www.virtualcolony.com/sac/ ), to build lists of viewable objects by constellation. I was very glad to be able to thank Duane in person, as he joined our group this evening. I heartily recommend his site, and it was fun to observe with Duane, as we compared his C5 with my NexStar5. They are both great little 'scopes.
Early evening views of Jupiter and the Orion nebula look good, even through the haze. It was interesting to compare the views through the assembled telescopes. David Silva's Traveller gave the crispest views, but all the telescopes acquitted themselves well, with the sad exception of Adam Shiffman's GP mount which was RIP for the night, with sticking drive motors.
LEO looks good with M65/66 clear and the dimmer NGC 3628 visible in my 8" even before full dark. It was more difficult in the N5, but better later in the night. So picking up from where I left off last time, I returned to NGC 2903. This is a very pretty galaxy, with a nice oval shape, and a disturbed look, perhaps bumpy is a good description. Three stars form a triangle at one end, and a pair of stars bracket the other end. Projecting a line off that pair, is a very faint smudge, NGC 2916, which was visible only fleetingly with averted vision in the 8" at 85x power. The seeing is not as good tonight as two weeks ago, when 2916 was more easily held in view.
Moving back around the mane (or sickle) of LEO between mu and zeta, is NGC 3098. This was also very faint, and the shape indeterminate, just a fuzzy bit in an otherwise clear star field. The core looks stellar but faint.
Dick Flasck successfully distracted me with a great view of the NGC 3185,87,90,93 group of galaxies (between Algieba and zeta LEO), which I had seen two weeks before. Three are really nice in his 17.5" with 3187, being a lot fainter and not immediately obvious.
I looked for the 2911/14/19 group off the end of LEO's foreleg, inside a triangle of stars (omicron, xi and omega). These galaxies are very faint, and barely detectable. I couldn't honestly say that I had more than one visible, nor which of them I could see. This is one group I'll need to revisit, at a later date.
The dew point was exceeded, and moisture had made my papers limp, as well as fogging up the Telrad and finder scope. I spent a few minutes more looking at brighter stuff, before giving in to the elements (1°C/90%+Humidity).
M51 was very nice, and really showed the difference aperture makes. Clear spiral lanes and distinctly countable arms in the main galaxy, along with structure in the companion, from Dick's 17.5' compared with a barely visible spiral in my 8". Then two fuzzy dots in both 5" SCTs, leave little doubt about the advantages of big iron :-)
M101 eluded my fogged up NexStar, but was really nice in the 8" and in Duane's C5.
Later in the evening, after Dick had packed the big Dob away, and my NexStar had dewed up, we also compared M13 in the C5 and the 8". Despite being low in the sky, and thus in the hazy horizon, M13 still shines through, surely one of the best sights in the Northern sky. With resolvable stars at every depth, it is seemingly endless to the core.
M104 was very nice, with the dark band clear, and the upper(?) halo visible.
Daylight savings crossed me up here, as I looked for Mars, expecting it to have already risen. I'd have needed to wait another hour or so, just to get to the same relative time as two weeks prior. Antares rose, and I tried to get a peek at M4, but the hazy light dome from Healdsberg really got in the way.
We packed up around 12:30pm, after a quite enjoyable evening.