The sky here was clear late enough to find the April 5 12-hour UNID again. Mike McCants had search orbit predictions and his 8-inch dobsonian telescope with 12x80 finder scope. We did not find it at the first prediction point only 17 degrees above the horizon, but I saw it in binoculars several degrees south of alpha Sextans, and Mike got it in his finder scope in a minute or so. Using the 8-inch telescope, it was easy to see that its flashing is very complex, to the extent that it sparkles. Its brightest flashes, +5.5 or possibly brighter at a range of several thousand kilometers, are very sharp and quite impressive, and its flash period is very close to 10.5 seconds, but some secondaries are visible in binoculars. Unfortunately, I managed to lose it after Mike had only seven minutes of observations. Mike was writing some data down, and it was out of the field by the time I looked, and I was hesitant to move the scope enough, and it got away. Maybe it got much fainter about that time, because it was not to be found. I also goofed in that I'm not sure which of my stopwatch clicks were for which sky positions. My flash timings were from 4:42:45.85 to 4:45:23.25, from several degrees south of alpha Sextans to very near or perhaps a little north of it. However, Mike got three useful position measurements, so weather permitting there's some hope of finding it again! Here's a pseudo-PPAS report, in that I don't know what designation to use for it. 50-999ZZ 00-04-07 04:45:23 EC 157.4 0.3 15 10.49 mag +5.5->inv; sparkles Location was BCRC: 30.314N, 97.866W, 280m. In the last few days all of the Iridium flares for which I've looked have been pretty close to predictions. In a message from the Meteorobs mailing list I saw a reference to an Aviation Week article that apparently says that their re-entries will be uncontrolled. I still wonder what the chances are of any fragments surviving to reach the ground. That references was under "Uncontrolled reentry planned for Iridium satellites", near the end of this page: http://www.geocities.com/skyweek/mirror/184.html Ed Cannon - ecannon@mail.utexas.edu - Austin, Texas, USA ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Fri Apr 07 2000 - 03:04:55 PDT