Friday, September 6, 2002

TACos at Bear Valley observing site.

I was at the "southern" (private) Sierra foothills observing site, outside Bear Valley near Mariposa, for two nights.

Friday night I looked at many brighter objects for a deep sky article I'm doing for the SJAA. Lots of fun seeing how much detail was visible in such objects as M52, NGC 7662 and NGC 40. I had a gorgeous field of galaxies around NGC 7619 in Pegasus. This was all using an 18" f/4.5 Obsession. The clear winner the first night was 7662 - where I used magnifications ranging from 103 to 172 to 294X. Here is some of the report - at 103X very bright and distinct turquoise blue (planetary nebula). Central star visible occasionally direct and more frequently averted. No filter view at 103X hints at a bright core with dimmer smaller halo. At 172X I see two shells more obviously - possibly a number of stars, dim, in the bright shells. A dim large envelope surrounds the two bright shells. A star to the NE seems to be in a brighter portion of the outer shell (envelope). With an Orion Ultrablock filter the center is dimmer and takes on an annular appearance. The outer envelope is more pronounced with this mag and filter. At 294X the planetary is clearly annular with brighter extensions a short distance away to the ENE/WSW. At this mag with the filter a glowing somewhat irregular "neon" ring shows, overlaying the inner and outer sections. There are no stars embedded, but may be some bright small sections of bright ring protruding into the outer halo, looking like pinpoint stars.

NGC 40 was a wonderful contrast - As large as NGC 7662. Bright central star with dim halo containing two shells. Seems at 294X to have two dark lanes surrounding the central star, arcing slightly around it to the N and S. The western of these lanes seemed more pronounced. A star sits at the S tip and a very dim star at the E edge. Looks almost like a tight spiral galaxy with a western arm curving around to the S and an E arm curving to the N.

Nice objects.

The second night I began by finding Pease 1 in M15. One of the other observers had a finder chart off Doug Snyder's site. As time wore on other observers were needling me about how long I was spending. Upon returning home I read other reports where people had spent up to or in excess of 2 hours hunting down the dim planetary. Not until I returned home did I truly feel I had found the planetary. The seeing while I was attempting this "star hop" within the globular was spotty... and it was exacerbated by an 1-1/4" OIII filter, which I found useless to blink the object or to have in the eyepiece.... it seemed very difficult with the filter in place to get sharp focus. So I found it without the filter, which allowed the stars (and the star-hop directions) to be easier to follow. When I completed the observation, two other people who had said they wanted to "do it next" declined :-) I would like to do it again under a bit steadier skies (I was at 428X, which was as high as the sky would allow).

I then went on to a list of Abell Clusters Steve Gottlieb suggested as summer targets. AGC 2197 was awesome, and I was hitting virtually every object I went after in this and other Abell targets that followed. I was easily into the dim 15's and brighter 16's. I hit 21 galaxies all within a short distance of initial location (Steve's note says he observed 25). I also thoroughly enjoyed AGC 2666. Quite a night!

Temps were very nice, better on Saturday, when I wore thin thermal over jeans and t-shirt with lightweight PolarTec shells. I turned in around 4 a.m. Sunday morning.

I can't wait to get out again next month. Same place for me on 3rd Q, then CalStar.