A Nova and a Geosat (and then Moonrise)

by Robert Sheaffer


I decided to take advantage of the approx 2 hours of darkness (well, semi-darkness, it *is* my backyard) before the moon rose to see what I could see in my Celestron Nexstar 11. Nova Sagittarii 2001 No. 3 was recently announced (see http://www.aavso.org/alerts/). It is reported to be of about magnitude 7.0, at 18h 11m 46s, -30 deg 31'. I did a GOTO that location, and indeed did see an orangeish star at that location that looked to be approx mag. 7. There was a brighter star approx mag 6 (also orangeish) below it within a half-degree, presumably TIC 7392-0356. There are no other stars as bright as mag 7 nearby, and the scope GOTO was working dependably, so I'm pretty sure I did see it.

I also wanted to see if I could pull in a Geosat, using the GOTO function. I used Mike McCant's HIGHFLY program (see http://users2.ev1.net/~mmccants/), along with the latest copy of the satellite elements file "geo.tle", which contains up-to-date orbital elements for geosync satellites. While most of the birds have an estimated magnitude of around 12, the calculated magnitude for GE-1 (which carries Fox Sports and a bunch of other stuff) was all of 7.8. From the Bay area, this bird hangs around at altitude 43 deg., az 150 deg., at all times. For some reason, while HIGHFLY can give you a very accurate calculation of RA and DEC, it rounds off Alt-Az to the nearest degree! So, I did a GOTO to the predicted RA and DEC for the present time, put in my wide-angle eyepiece, and almost immediately spotted a star that was moving with respect to the rest of them. The magnitude estimate of approx 8 indeed appears to be fairly accurate. First, I turned tracking to "off", then turned the scope off completely as I was putting my stuff away. GE-1 stayed centered in the field all this time, while the background stars drifted past it. In case anyone wants to try to see it, I've included the predictions for the next two days:

24315 GE 1 96 54A 486** -.2 ElDy
PDT ALT AZ M RANGE RA DEC
Sept. 7
8:10431508.02224519 37.01-5.86
8:40431508.02224620 7.08-5.86
9:10431507.92224620 37.15-5.86
9:40431507.92224721 7.23-5.85
10:10431507.82224821 37.30-5.85
10:40431507.82224822 7.37-5.85
11:10431507.82224822 37.43-5.85
Sept. 8
8:10431508.02224519 40.95-5.86
8:40431508.02224620 11.03-5.86
9:10431507.92224720 41.10-5.86
9:40431507.92224721 11.17-5.85
10:10431507.82224821 41.24-5.85
10:40431507.82224822 11.31-5.85
11:10431507.82224822 41.38-5.85

We'll have a few moonless hours these next few days. While I can sometimes glimpse the Milky Way from my back yard, my Nexstar is craving a dark sky. Is anyone goinf to Monte Bello Friday or Saturday? Preferably, somebody with a Permit?