Hi Jonathan and List, As was earlier pointed out, the Tucson observation was certainly of ETS-6 (#23230), a well-established bright flasher. Its repeating orbit (5 revs in 3 days) favors observations every three days. Initial efforts to determine a spin axis for this dead satellite were made in July of 1998. At that time, typical flashes were about magnitude +1 to +2 depending on the range to the satellite (the orbit is fairly eccentric). At the end of the month the flash period was measured to be 16.20 seconds (Willie Koorts). By 9/21/1998 the period was down to 15.0 seconds (Mike McCants), and Ed Cannon measured it at 14.1 seconds on Jan 11, 1999, and a few days later he mentioned seeing flashes as bright as -1. The flash period has continued to decrease over the years: 09/21/1998 15.0 Mike McCants 01/11/1999 14.1 Ed Cannon 04/17.48/1999 13.20 Tony Beresford 04/22.63/1999 13.105 Tony B. 04/25/1999 13.059 Tony B. 04/26/1999 13.050 Tony B. 04/28/1999 13.019 Tony B. 04/29/1999 13.019 Tony B. 5/1.624/1999 12.982 Tony B. 5/2.45/1999 12.979 Tony B. 6/3.583/1999 12.619 Tony B. 09/18/1999 ~11.5 Ron Lee 12/09/1999 11.369 Steve LaLumondiere 12/12/1999 11.360 Steve L. 12/14/1999 ~11.4 Mark Hanning-Lee 12/15/1999 11.354 Steve L. 12/18/1999 11.349 Steve L. 01/05/2000 11.312 Steve L. 01/05/2000 11.3 Michel Jacquesson 01/11/2000 ~11.3 Rob Matson 01/17/2000 11.28 Ed Cannon 02/01/2000 11.29 Don Gardner 02/16/2000 11.20 Don G. 02/27/2000 11.17 Tony Beresford 03/04/2000 11.154 Tony B. 03/07/2000 11.142 Tony B. 03/10/2000 11.133 Tony B. 09/30/2000 10.124 Rainer Kracht 10/03/2000 10.116 Rainer K. 10/06/2000 10.108 Rainer K. 10/09/2000 10.098 Rainer K. 02/17/2001 9.76 Mike McCants Jonathan asked: "A magnitude of 1 of a geosynchronous satellite seems > quite bright to me (if it was in a 300x300 orbit, then it probably would > have looked > like an Iridium flare). Does anyone know what are the brightest > geosynchronous > flashes observed?" > I'm guessing around magnitude 0. ETS-6 is eccentric and subsynchronous, so it's not fair to include it if you're strictly interested in the brightest GEO flashers. Cheers, Rob ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www.satellite.eu.org/seesat/seesatindex.html
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