Dbls from Cupertino, 12 Feb 2005

by Bob Jardine


Observing Report -- Home (Cupertino) -- 12 Feb 2005 (Saturday)

It was Saturday, just after new moon. The weather was highly variable. The CSCs predicted a few hours of “blue” prior to a long stretch of clouds, but they don’t update frequently enough for such highly variable weather. I waited and waited, watched the satellite images, watched others stand down, watched the clouds move in. Finally I stood down too. Boy was I p*-ed off.

There was going to be a nice occultation of 88 Psc by La Luna. Grazing in Monterey, Pinnacles, and on to Fresno. I had hoped to go to Coyote, to at least be closer to the graze line. But I stayed home.

Surprisingly, at 7:00, about 30 minutes before the occultation, I could see the moon. So I set up my TV NP101 on the back deck. Sure enough, I could see the star, quite obviously in the moon’s path. If you haven’t watched one of these -- do it. You can really get the impression of a really huge object very slowly, but inexorably, moving in to crush a little tiny object. You almost feel sorry for the star!

But clouds were moving. By 7:15, although I could still see the moon, I couldn’t see the star. Missed the occultation. But there were still pretty large patches of sky open, and the clouds were moving so fast, I decided to leave the scope set up. I went inside for dinner. Came back out at 8:00. The sky was completely clear! I’m not kidding -- not a cloud in the sky.

First, I kicked myself for not going to MB anyway. It is only a few miles due West of me (as the crow flies), so I knew it must be clear there. Oh well, split milk. So I stopped kicking and started splitting -- double stars, that is. I took most of this list from Dickinson’s Mag 6 Star Atlas -- in addition to a good beginner atlas, it has a fine list of objects.

It turned out to be a fine night on the back porch. A little dew, but not bad. Clear skies (mostly) for almost 3 hours!

(Warning: I split doubles for fun, not science; there are PA estimates below, and occasionally separation estimates; I do these for practice, and compare them against the published values, but I just use the drift method for PA and "eyeball it"; and I’m very happy if I get within 20 degrees. So there.)

23 OrionisVery wide. splits even in my “finder” (35mm Panoptic). Viewed at 60x and 108x. PA estimated 10 to 20 degrees. Primary is white; secondary is off-white.
33 OrionisBy contrast, very close. splits (barely) at 108x. clean at 193x. PA est 10 to 15 degrees. Est sep about 2 arcsec or so. No color seen.
52 OrionisSuspected only. very, very close (suspected at 270x). PA about 20 to 30 deg (or 200 to 210 -- I can’t tell which is the primary). I’ll need to try this one again with more aperture. Normally, I could go to higher power with this scope, but the wooden deck has some bounce, and the image wiggles too much, even at 270x.
59 Orionisvery obvious wide companion at PA about 300. However, with more power (visualize the tool man: “MORE POWER!”), there is a closer, much dimmer, companion at PA about 200 to 215. Barely visible -- on the edge of my visibility limit tonight. Not super close, however.
Struve 750dbl in Orion -- this one is interesting, as it is in the OC 1981 (top of the sword). PA about 45 degrees, secondary about 2 mags dimmer, quite close -- splits cleanly at 108x, but only barely. A nice clean split at 270x.
14 Aurigaenice; pretty wide at 77x. PA est 250. secondary is at least 2 mags dimmer and less white.
26 Aurigaepretty close at 77x. PA est 270 to 280. At least two mags dimmer and less white. Similar to 14, but a little closer.
88 Leonisclose and very dim at 108x. at 193x, pretty close and very dim companion -- can see it direct, but barely; need to use AV to get PA (est. 300 to 320). Must be at least 3 mags dimmer.
90 Leonisis this a triple? quite dim and wide companion at 77x. PA maybe 250. But at 108x, the primary splits, but is very close. At 193x, it is a close dbl with about 1 mag difference; PA about 210 to 230. Both white.


Posted on sf-bay-tac Feb 14, 2005 20:26:08 PT
Converted by report.pm 1.2 Feb 15, 2005 18:46:22 PT