by Rich Neuschaefer
I had my AP 155EDFS (155mm f/7 APO refractor) and my AP Stowaway 90 mm f/7 (92mm f/6.6). Both scopes were working well. I did most of my observing with the 155EDFS. The Moon was showing lots of detail. Saturn looked very nice with a shadow of the planet on the rings and the crape ring was easy to see. Jupiter was showing lots of detail, festoons, white ovals and GRS.
Late, after midnight I tried splitting Porrima. It was easy to see that it was a double star but no black line between the Airy discs. It was just at the point of starting to show a figure eight. I was using well over 400x. One of the observers though maybe it would have shown the split if the seeing had been dead steady. I was happy the way it looked given it is very close for my 6.1" scope. Two years ago it was easy to see a black line between the two stars. I also tried Nu Scorpio. All four components were easily split even though it was nearly two hours from transiting. One of the double star experts suggested trying Iota Leonis. It was a nice unequal double. The bright star is white and the dim star is yellow. He also suggested trying Rho Leonis another interesting unequal double.
I didn't look closely at stars early in the evening when, I think, the seeing was better. Near 1:00 am some of us were trying to split some tight double stars. The seeing was not quite good enough to show a first defraction ring when looking at Porrima using high power.
On other nights with the same telescope (155mm f/7 APO) but up the road more, a private site close to Montebello, Porrima would show nice first defraction rings and Airy discs.
Most of the time Porrima looked very elongated. Only at the best moments did it look like it was just starting to show a figure 8 (slightly pinched).
One of the people at the star party thought it was about 0.70. At 0.51 I'm really happy we could tell it was a double.
It was a great way to kick off the PAS Foothills Park star party season.
Posted on sf-bay-tac Apr 26, 2004 16:05:59 PT
Converted by report.pm 1.1 Jul 10, 2004 19:42:29 PT