My Observing Log: January/February 1999

6:00 p.m. 13 January 1999 PST (0200 14 January 1999 UTC)

It has been a long time since I took the telescope out to observe, for a variety of reasons. Well, I expect that to some degree; it's winter, or at least what passes for winter in California, and it simply has been very cloudy out. But in the meantime, I decided to supplant my equipment list. And it turned out not to be as expensive as you might think.

I have long wanted a tripod of some sort. If you read the other entries in this observing log, you might notice that I have two basic spots that I use: the Table and the Roost. Both are fairly stable; the Roost is actually the flat roof (Californians, go figure us) of our town house unit, and the Table is a plastic resin picnic table, but it's weighted down by a 50-pound concrete slab, so it's reasonably jiggle-free.

Nonetheless, neither is very portable; using the Table somewhere else would require me to disengage the concrete slab, and it is not really meant to be disassembled each time; and of course the Roost would be fairly expensive to tear away from our house. So a tripod would seem to be the order of business.

Two problems. One is the price, about $230 for a basic tripod that mates with the C5+ wedge. Not an insurmountable problem, but since I laid down over a grand for the C5+ itself (including shipping), I wasn't eager to fork over another couple of hundred bucks. Still, if that was what it cost, then I would do it, sooner or later.

The other problem was the height of the tripods. I like to sit while observing, and none of the tripods available would leave the C5+ at a height that would be comfortable to use while seated at an ordinary stool. The alternative would be a bar stool or a specially-designed observing chair, but I'd then have two things to buy. I have ordinary chairs and stools at my disposal.

I decided instead to get a Black and Decker mini-workbench. It costs about $60 or $70, and it turns out to be remarkably stable for astronomical purposes. I used it tonight to look at Jupiter and Saturn, and also some open clusters in the region of Auriga and Gemini.

The workbench is fairly easy to put together. It folds out in a matter of seconds. Its primary disadvantage is that it weighs about 20 or 30 pounds (I haven't measured exactly), but to me that is more than balanced out by its much lower price and also its lower profile. It's perfectly set up for me to use my folding stool.

Seeing was moderately bad tonight, with moments of average seeing. Jupiter would shimmer back and forth, and I would see hints of a sharp edge now and then, but it wasn't a great night for observing planetary details. I instead decided to test the stability of the workbench, and it worked very well. It about doubled the damping time for vibrations (a typical nudge would last about five seconds instead of three), and was unaffected by 10 mph winds.

Saturn was higher in the sky and offered somewhat better viewing. Still, Cassini was intermittent at best, and when it did appear, it was less a clear-cut ring of darkness and more a very gradual dimming near the center of the ring system. (Yes, I did check my collimation, or at least as well as I could.)

I used my homemade planetarium program to locate M36, M38, and M35. M35 in particular was very impressive. It has the much dimmer NGC 2158 to its west south-west, but while I was able to starhop to where it should have been, I couldn't find it through the scope. (The planetarium program displays it, however.)

6:00 p.m. 27 January 1999 PST (0200 28 January 1999 UTC)

This was a relatively short observing session, as I only had a limited amount of time before I had to go make some dinner (!). I've been wanting to bag the E component of the Trapezium in M42 at the very least, and spot F too, if possible. I knew collimation was going to be a crucial issue, so I spent about 10 or 15 minutes tweaking that until it was pretty darn good. I think it helped a great deal.

I tried the 15 mm Plossl both with and without the Barlow. It was definitely easier without the Barlow. The split is wide enough (about four arc seconds, I think, for both A-E and C-F separations) that 83x was plenty enough magnification. The E component was clearly visible with averted vision, and at times (probably about half of the time) was evident even with direct vision. This even though a 10-day-old moon was shining over Orion's shoulder the entire time.

F was a lot harder; it's separated from C by about the same amount as E is from A, but C is considerably brighter than A. There were just a few times (maybe 10 percent of the time) that I thought I could see it, but it was hard to tell if it was F or if it was a flare in C due to uncertain seeing.

M43 could be seen rather easily as a small puff north of the main nebular mass.

The seeing was OK, but not great, after all. Saturn was steady but not crisp. The Cassini division was present but mushy. I tried Plato on the moon, but it was a couple of days too late for that (the terminator already had passed), and while I think I could see craterlets, I don't think I would have found them if I didn't at least have some clue as to how they were arranged. Jupiter was bright, but low enough on the horizon that it too was mushy, and exhibited a good deal of color separation.

After a while, it got too windy, and I had to go inside.

6:30 p.m. 17 February 1999 PST (0230 18 February 1999 UTC)

Tonight, seeing was so-so, a 4 or 5 out of 10. It was notable because I had just picked up an 9 mm orthoscopic from Pocono. They believe they're the same well-known orthoscopics sold (but not manufactured) by University Optics. It does have a circle-T on the barrel, which might stand for Tanny, the manufacturer of the UO orthoscopics. (Update: It was noted on SAA that the circle-T stands for Tansutzu, which indeed manufactures the UO orthos; Tanny is short for Tansutzu.) Used alone on the C5+, it yields 139x, a good starting point for observing planets; with the Barlow, it gives 278x, about as high a magnification as I'll typically be able to use.

I tried it out on Saturn, the only planet high enough at the time to observe cleanly. At 139x, Saturn was crystal clear; at 167x (the 15 mm Plossl plus the Barlow), the image clarity began to break down a bit; and at 278x, it was just plain mushy. The Cassini division showed best at 167x, not too surprisingly. It was visible at 278x but nowhere near as sharp.

I'll report more after I've used it a bit more.

6:30 p.m. 23 February 1999 PST (0230 24 February 1999 UTC)

Not much to report today—I only had about 20 minutes or so to do anything—except of course that magic conjunction of Venus and Jupiter. It surely was amazing to see them that close together. I tried to record the event with afocal (full camera with full telescope) shots, with both the digital camera and the SLR; we'll see how those go.

Venus was so bright that its glare shot out most of its shape; I could barely make out a halfish phase. Jupiter was much clearer; it and three of its satellites were clearly visible against a wan blue sky. Jupiter showed clear but pale banding, possibly because of the twilight glare.

11:30 p.m. 27 February 1999 PST (0730 28 February 1999 UTC)

This night had the best seeing I've ever experienced—solidly a 10. Out-of-focus diffraction rings were absolutely steady and clear, and perfectly symmetric. I took advantage of the conditions to observe Mars, then about 30 degrees up in the south-east.

Mars is small! I knew that, but it's still surprising at first glance. Like Saturn, it did appear to grow while I continued observing it. At the time, the central meridian was 25 degrees longitude and two primary dark patches, Mare Erythraeum and Mare Acidalium, were clearly visible at 278x. Chryse might have been evident as a barely whiter patch in between the two maria, but it was hard to tell. I can't wait until later this year in April, when Mars's disc will be 60 percent larger.

I also spent some time looking at the full moon earlier in the night, when the C5+ hadn't cooled down quite yet. Even then, it was obvious that the air was going to be very steady and Plato's disc showed two of the craterlets clearly and another one—the singlet at eight o'clock—made an appearance from time to time, tube currents permitting.

Copyright (c) 1999 Brian Tung