Last night Mike McCants and I had some fun with three geosynchs currently flashing over the Americas. TDF 2 (20705, 90-63A) was exhibiting a period of about 20.3 seconds with an asymmetrical secondary maximum. The satellite was only about +7.5 at the brightest (observed in Mike's 8-inch telescope), but the last time around -- a couple of months ago -- it was easily as bright as +4.5 for up to 45 minutes per night. So it's a matter of finding out when the brightest flash episodes are occurring. I thought I'd try for Gorizont 17 (19765, 89-004A) with my binocs, and I found it okay, flashing to about +5. The problem was that very nearby was another one about +6! I grabbed the predictions and found that it was less than a degree from Gorizont 16 (19397, 88-071A)! They both fit within the one-degree field of view of Mike's 8-inch, and they cycled so that they flashed within about 1.5 seconds of each other! I had used up the clicks on my stopwatch, so this is by "word of mouth" and relying on my memory when I should be sleeping, but Gorizont 17's period was 81-plus seconds and Gorizont 16's was 93-plus. Mike noticed that Gor 17 had a secondary flash, and sometimes it was not easy to distinguish the primary from the secondary. Last night I was writing down some approximate positions to make sure of the ID of an unexpectedly bright object, when suddenly the paper lit up, and I looked up in the sky in time to see the tail end of the predicted -8 flare of Iridium 81! Guess I should have had WWV blaring or something to remind me of what time it was.... It was obviously bright enough to illuminate my predictions! Observing location was 30.314N, 97.866W, 280m. A few minutes ago I saw USA 32 (19460, 88-078A), seemingly reasonably close to the prediction -- just below the Pleiades! And it passed just below Saturn a few seconds later. It did one of its typical one-power flashy-sparkly episodes a bit south of Saturn. 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 : Thu Aug 03 2000 - 03:13:44 PDT