Making the Best of Bad Seeing

Observing at Fremont Peak, 1996 Dec 14

Recent frontal passage across the central California coast left Fremont Peak State Park cold and wind-buffeted on Saturday, 14 December, 1996, and reduced seeing to devastatingly poor levels, but the high transparency of the storm-washed air produced good conditions for viewing faint fuzzies. I was too tired to fuss with much equipment -- I only brought my 63 mm "Baby Brandon" refractor, and did not even get around to setting it up -- but there were plenty of telescopes to look through.

All of the refractors ended up on top of the hill, in an area that the jealous are beginning to refer to as "Tasco Row". It was interesting to see a large-aperture Astro-Physics binoviewer done "the hard way" -- two proud possessors of new 180 mm f/9s were pointing them at the same objects and describing to each other what they saw. Audio interferometry, what more could you ask for? :-) With two-arc-second seeing -- Castor was split only occasionally -- we couldn't say much about the performance of the big refractors, though they were both giving nice views of M42/43 at low magnification. There was the usual heated discussion about whether we could see color in the nebula -- one owner said yes, and one no -- isn't it amazing that one can get such a difference in performance in two telescopes of the same type and from the same manufacturing run? I myself saw warmer tones just south of the dark, more or less east/west bar that some people call the "wings" of the nebula, and on prompting from one owner also detected a clear pinkish tinge in the much fainter area south of the Trapezium.

Also in this area was a four-inch "Zeisstrophysics", a Zeiss lens mounted in an Astro-Physics tube assembly. Its owner had it set up on an old Unitron four-inch altazimuth mount, one of the ones with the counterweight sticking out forward and down, not the old, old bent-fork unit. I had a nice view of Saturn through this instrument at low magnification; color correction appeared excellent.

Someone also had a Celestron 80 mm f/5 refractor, one of the new ones. Prompted by my recent posting about vignetting in the Orion ShortTube unit, he had checked the Celestron and found it operating at only 55 mm aperture. He had fixed the problem recently -- with a h*ck s*w -- but had not completed optical evaluation of the repaired unit.

Down on the flats behind the ranger's house was the usual assortment of stuff, plus an assortment of less common types. The latter included the first Meade 7-inch Maksutov that I had seen, and a Questar 7. Both of the big Maksutovs took a long time -- hours -- to come to thermal equilibrium in the chilly air. We tried comparing them with views of Saturn at 160x to 220x; seeing occasionally went clear for long enough to show that both were doing a good job, but again, critical comparison was impossible. It was not obvious that the Meade's cooling fan was much help getting it to settle down. Later in the evening I had a nice view of planetary IC 418, in Lepus, through the Questar at 300x.

One person had a Meade 12-inch LX200 set up and running well. We looked at several bright deep-sky objects with it. M76 was pretty and compact at 87x, M74 was visible even at as much as 254x, though better at 152x. At the latter magnification, I could see central condensation and perhaps a little elongation outside it, all before moonset. M1 showed both the plasma cloud and a hint of mottled structure outside it. NGC 253 was beautifully textured at 87x. A comparison view in the Meade 7-inch at 76x did not show the texture so well, but it was present. Later on, we used the 12-inch at 152x for a view of NGC 2359, "Thor's Helmet". The object was easy to see without any special filter, but an OIII filter made the "cap" and "wings" stand out obviously.

I had plotted on my charts the positions of three of the small satellite galaxies of M31, which are creatively named Andromeda I, Andromeda II, and Andromeda III. After moonset, I borrowed the use of a couple of telescopes to find them. At 110x in a 14.5-inch Dobson-mounted Newtonian, I and III appeared about equal in size, but III was brighter. It is hard to judge the size of such diffuse objects, with no sharply-defined edges, but what I was seeing was perhaps 7 to 10 arc minutes diameter. At 60x in a 12.5-inch Dobson, II seemed smaller and fainter than either I or III, after allowing for the difference in aperture. I myself did not look at any of these objects in both telescopes. The RASC handbook gives positions for these objects, and says they all have magnitude 13.5, but reported magnitudes of faint diffuse galaxies do not correlate well with visual appearance. I believe my report is also the consensus of the several other observers who saw these objects.

Jay Reynolds Freeman; last updated: 1996 Dec 15