by Albert Highe
Weather forecasts for the weekend looked dismal. Since the Clear Sky Clock, satellite images, and local forecasts all look great for Dinosaur Point for Thursday night, I decided to take advantage of the break in the weather. The only concern was the rather high winds in the Bay Area.
My van was buffeted by winds on the way to San Luis Reservoir. However, the wind was calm at the Dinosaur Point parking lot when I arrived at 3:30PM. By judging the appearance of the lake, I estimated that the wind was no more than 10mph out on the water. It was warm enough to take off my shirt and bask in the sunshine. Only occasionally did a puff of wind make it to the picnic tables.
Five others also made it to Dino: Denny W., Peter N., David K., Bob J., and Robert H.
At sunset, the temperature quickly dropped to the mid 50's. The air was very dry. The relative humidity was only in the mid-30's. During the night, the temperature eventually made it to the mid-40's. The RH never climbed higher than 70%. About half the time we had no wind at all. About every hour-and-a-half we would get about a half hour of light wind strong enough to turn the pages of my atlas and observing notes. The combination of moderate to no wind, moderate temperatures, and low humidity, made for a comfortable and pleasant night (at least until half of us left at Midnight).
Seeing was decent early on. Jupiter showed quite a lot of detail at 210X. Five stars were visible in the Trapezium. The sixth was visible intermittently.
| Telescope | 12.5" f/5 ultralight |
|---|
After the traditional barbecue, most of us started observing the highlight for the night - comet Ikeya-Zhang (C/2002 C1). It has brightened considerably and grown a beautiful long and bright tail since I began to observe it a couple of months ago. It was an easy nekked-eye object. I estimate about mag 4. In my 80mm finder, the tail was visible out about 3°. At higher powers in the main scope, the nucleus was a tiny brilliant point surrounded by a wide circular halo. A very bright tail cut across the entire f.o.v., gradually fanning out from the circular halo.
I spent some time observing objects I won't see much longer. I put an H-beta filter on my finder eyepiece and enjoyed seeing the entire California Nebula in the f.o.v. I then switched the H-beta filter to an 18mm Radian eyepiece in the main scope. The Horsehead Nebula was an unmistakable irregular dark patch blotting out a section of the long thin brighter portion of emission nebula IC434.
Another highlight was the galaxy group in the vicinity of NGC3430 in Leo Minor. I hadn't observed this group for about five years. As expected, I saw more than I did before. I could almost fit five galaxies into the f.o.v. of my 14mm Radian at 113X.
| NGC3430 | Mag 12.1 | 4.0'X2.2' |
|---|---|---|
| Clearly the brightest of the group. Somewhat elongated oval with near uniform brightness. | ||
| NGC3424 | Mag 13.2 | 2.8'X0.8' |
| Narrow elongated galaxy 6' away from NGC3430. | ||
| NGC3413 | Mag 13.1 | 2.2'X0.9' |
| Appeared smaller, fainter, and less elongated than above. | ||
| NGC3395 | Mag 12.5 | 2.1'X1.2' |
| NGC3396 | Mag 12.6 | 3.0'X1.2') |
| Very close pair only 0.5° away from NGC3430. Near equal magnitude galaxies. Both are slightly elongated, NGC3396 more so than NGC3395. Long axes are oriented about 100°. |
Also, there is a nice quartet of galaxies in Leo that fit within a single moderate-power f.o.v.
NGC3691 (12.4, 2.5'X2.0'), NGC3684 (12.2, 3.0'X2.1'), NGC3686 (11.8, 3.2' X2.5'), and NGC3691 (13.4, 1.4'X1.0'). The first three are similar magnitude and size ovals, nearly equally spaced along a line. NGC3691 is a somewhat fainter oval lying almost along the perpendicular bisector of this line.
Another close quartet in Leo is NGC3605 (13.1, 1.6'X1.0'), NGC3607 (11.0, 4.9'X2.4'), NGC (11.8, 3.2'X2.6'), and NGC 3599 (12.6, 2.7'X2.1). All of these just fit into the f.o.v. of my 14mm Radian. NGC3607 and NGC3608 are a pair of bright ovals, but all are rather easy to see.
In addition, I found nearby UGC6296 (14.5, 1.4'X0.4') which lies 15' from NGC3607. I could hold this faint patch with averted vision. A faint star adjacent to this galaxy hampers the view a bit.
I finished the night with a quick tour through some of the bright galaxies in Coma Berenices and Virgo. It's a real treat to walk through Markarian's chain after viewing faint fuzzies. I also made a stop at one of my favorite edge-on galaxies, NGC4216 (10.0, 7.3'X1.7'). It's a nice long, thin spindle with a very bright, small nucleus. I could also detect its major dust lane.
As I left about 12:30AM, the wind atop Pacheco Pass was noticeably stronger than down at Dino, and the temperature was 7-8° colder.
It is always a pleasure to get five hours of quality observing in mid-week.