Iridium flare intensity
Ed Cannon (ecannon@mail.utexas.edu)
Wed, 07 Jan 1998 20:24:35 -0600
After some days of clouds and rain, the sky cleared this evening.
>From outside my office, I was lucky enough to see a magnificent
flare from Iridium 30. Adapted Iridflar output for a "generic"
Austin location (30.30N, 97.75W, 150 meters):
Iridium Sun Fl Maximum Flare Ir
Date UTC Time UTC Azm Al Rnge N Al Mag Lat. Long. #
-----------------------------------------------------------------
98- 1- 8 00:16:35 048 67 838 A -6 -8 30.305 -97.712 30
Since the Moon was in easy view, I made a quick back-and-forth
one-power comparison. It appeared to me that the Iridium flare
was much more intense than the Moon's light. I don't know the
physics and/or optics to know what to make of that in terms of
apparent magnitude. Iridiums are nearly point sources, while
the Moon is not. In any case, I'd say that, in some very real
sense, the Iridium flare was brighter than the Moon, which
tonight is about 67 percent illuminated according to:
http://saatel.it/users/lore/moon.html
Also saw 4 others sats (only a few bright passes tonight).
Ed Cannon
ecannon@mail.utexas.edu
Austin, Texas, USA