Pretty good night last night at Grant Ranch. We had about 10-15 observing instruments, ranging from 2 pair of large tripod-mounted binoculars through small reflectors (4.5", 6"), a number of 8" SCT's, a "home-made" 6" refractor, with a C11 and a 20" dob on the upper end. As usual I had my C-8 on a GP mount. The weather was fine: no clouds, no dew, reasonable transparency, and nice temperatures (it actually got warmer later into the evening before cooling off considerably just before midnight). Seeing was not so good early on but improved past 11PM. The atmosphere must have been fairly dry, as the San Jose light dome did not invade as far as it usually does from the west.

Because I was set up out on the far right flank, I seemed to miss all the early troop of campers who came by for looks. With no one to show anything to, I went planet hunting. Starting at Beta Capricornus, I skipped south to a triange of starts, turned east and found Uranus pretty quickly. At 150X it showed as a pale bluish-green disk. Going back to the triangle of stars, I headed east and hunted down Neptune. This planet was a good deal more subtle. At 150X is was almost stellar. If you observed it vs. all the stars around it, Neptune was the only dot of light that didn't twinkle. To say it was an 'obvious' disk was a stretch. It did have a bluish cast to it. Looking at Jupiter this early in the evening was not rewarding; it was low and the seeing was terrible.

Next I went hunting for an object I've either not found or forgotten to look for or lost below the tree line for the past several sessions: the Helix. It's in roughly the same part of the sky as Uranus and Neptune, so I was hopping over there when my first public (a mom and 5-year son) appeared. As I was at the moment in the middle of a rather boring star hop (no sights along the way), I asked them to come back in a few minutes or I'd find them when I got to the Helix. Having made the committment, I was somewhat distraught at arriving at the proper location and seeing...nothing. Stuck on the O-III filter and *boom* the Helix leaped out at me. It was grey, fuzzy, more or less round (but not quite) and had slighlty less brightness in the center than the edges.

So, off I went to find my small bit of the public, who had since wandered down toward the next scope down the row, which happened to be the 20" dob. (As is usual--at least at the star parties I seem to go to--the person with the biggest scope always gets the public's attention first, so he was busy lecturing on globular clusters, along with views of M15.). The mother and son came back and viewed the Helix. After that I put on the diffraction grating (kids love color) and they looked at the spectrum of Vega. Then the mob of campers that had finished with the globular lecture came over and joined in on the spectrum viewing. We had a friendly contest on how many absorbtion lines they could find, and a little explanation of how absorbtion lines come to be.

Unfortunately, no bright K or M stars were up to compare against Vega, so that was the end of the stellar spectra for the moment. We got off somehow on the subject of the ages of stars and when I brought up Double Cluster as an example of a very young group of stars, it turned out none of the campers had seen it yet. So everyone had a good look at Double Cluster. After that, they all went off.

Alone again, I went next for 7331 in Pegasus. This is nice galaxy and pretty easy to see. Well, if that was so easy, how about 891? One of the advantages of hunting up 891 is that you get to star hop from Gamma Andromedae, and I tarried there a while soaking in the beautiful color contrast of that double. Eventually getting to 891, I may have seen it with averted vision. It was very faint (and not there if you looked straight at it), but a lighter patch of the right shape and orientation was present. While I was in that part of the sky, I thought I'd go look up a couple of old friends, M76 and M34. Both were easy to find and presented nice views.

Break time! Went to see what the other scopes were looking at. Most popular were Jupiter and Saturn, with M31, M27, 6781 (a bright planetary in Aquila), and M33 (in large binocs) also under observation. Seeing was settling down, and the two major planets looked really fine in the 6" refractor and the C-11.

When I returned to my own scope, the owner of the 20" dob. floated over and wanted to do some more spectrum stuff. We tried it out on his scope. Both scopes have about the same focal length (2000mm) but of course his has a much larger exit pupil (2.5X that of my C8) at the same magnification. The maker of the diffraction grating recommends a 2-3mm exit pupil. I use a 17mm eyepiece and get a 1.7mm exit pupil on the SCT, because I have to trade off magnification (which governs the apparent length of the spectrum from red to blue) vs. exit pupil (which determines its width). On the dob, the 17mm eyepiece gave the same spectrum length, but it was much wider since the exit pupil had gone up to 4.2mm. Moreover, the three main hydrogen lines of Vega were quite a bit narrower (probably due to the increased resolution of a 20" mirror vs. an 8") on the dob than on the SCT. They were just as obvious, though. Curiously, they were more curved in the dob than in the SCT (or perhaps the lesser width of the displayed spectrum in the smaller scope made them seem straighter). Thinking it might be interesting to display a pair of spectra right in the same view, we tried Albireo on the 20". Unfortunately, the width of the spectra of Albireo's two component stars was such that they almost completely overlapped. The SCT didn't work either, because it just doesn't gather enough light to make the spectrum of Albireo's fainter star very colorful or easy to see. We also looked at Capella's spectrum but could not see any obvious absorbtions lines. As I left, the dob. owner was saying he had to get a diffraction grating. Another convert to the cause.

The night had reached that indefinable state of quietude. Even the faint little zephyrs had finally died away. So I took a look at Jupiter and Saturn, and the seeing had improved markedly. Jupiter showed a number of bands and some details along the equatorial bands. Saturn showed Cassini's division all the way around (when the seeing permitted), the shadow of the planet on the ring, the shadow of the ring on Saturn, and one band on the planet's disk.

Packed it in when the Mark '47 eyeballs began to show signs of fatigue.