Could Iri 81 be tumbling ?

Daniel Deak (
Fri, 12 Mar 1999 00:09:49 -0500

Hello everybody,

      A friend of mine who is a new satellite observer was waiting for
a mag. 0 predicted flare from Iridium 81 at 00:30:34 UTC on March
8 when he witnessed instead a series of 4 flashing cycles of 3 or 4
seconds in duration with maxima at mag. 4 or 5. Azimuth was 122°
and elevation was 48° for the predicted flare with the sun being at 283°
Az and 18.4° below horizon.

      His coordinates are : 45°53'55"N, 72°25'59"W, alt. 87 m
Another observer a few kilometers away saw the same phenomenon.

      I also need help to identify a bright sat seen by another newcomer
in sat observing. It was around 23:40 UTC on March 7 while she was
waiting for WIRE to make a nice pass, she noticed a mag +1 to 0 sat
crossing  the Big Dipper just under Megrez going in an eastern direction.
ISS made a pass in this area 20 minutes later almost on the same path.
The only possible match I could find is 25166 Globalstar 1 Delta r,
one of the current decay watch candidates but with an elset dating from
Feb 25 (didn't know it was a decayer last Sunday). If I use a more recent
elset, the pass is much earlier. Anyway, its usual mag is around 3 or 4
based on recent obs by Russell Eberst.
Location of the sighting : 45°52'N, 72°30'W, alt. 85 m


Daniel Deak
St-Bonaventure, Québec

COSPAR site 1745 : 45.9483°N, 72.6539°W, 58 m., UTC-5:00

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