Double flare from Iridium 9

ROB MATSON (ROBERT.D.MATSON@cpmx.saic.com)
24 Jun 1998 17:36:41 -0800

Chris Wyatt asked about a double-flare that he observed from Iridium 10.
I tried using the coordinates and TLE he posted and assumed today's date (June 24) for his observation.  Iridium 10 was nowhere in the area.  I
thought perhaps he had confused Iridium 9 with Iridium 10, and sure enough
Iridium 9 (#24838) was predicted to flare to -6 at 8:37:57 UT (which I assume
is 18:37:57 local time for him).

Not sure what surface on Iridium 9 could have caused a second flare at
18:38:40 (when the satellite passed by Alpha TrA).  The sun-observer-satellite
angle at that time was about 134 degrees, so for the glint to have been off a solar panel, that panel would have to have been tilted 23 degrees away from
the sun.  --Rob

TLE used:

Iridium 9
1 24838U 97030C   98174.06126447 +.00000099 +00000-0 +28416-4 0 01853
2 24838 086.3964 007.6414 0004143 050.8004 309.3559 14.34219511053074