IR11 & 14, Superbird

Matson, Robert (ROBERT.D.MATSON@cpmx.saic.com)
Thu, 5 Nov 1998 12:33:13 -0800

Hi Everyone,

I've definitely been enjoying Iridium 11 and Iridium 14 for the last
week -- they put on quite a show.  Sometimes as many as 5
or 6 consecutive negative magnitude flashes.  Last night (Wed,
Nov 4th Pacific Time)  Iridium 11 was especially impressive
high in the west around 6:05pm PST (2:05 UTC Nov 5).  Peak
flashes were at least magnitude -3.

Iridium 14 was also bright, though not quite up to Iridium 11 --
perhaps mag -1 and occasionally -2.  This may be due to its
faster rotation rate.  It timed its period at 4.865 seconds +/-
.017 seconds.

I want to thank everyone who has been posting peak flash
times for IR11 and 14.  I can barely keep up with all your
data!  I'll be sure to post any findings as soon as I've reduced
the most recent flood of data.

Despite the nearly full moon, I also managed to time Superbird
last night for the first time in two weeks.  The period has
definitely started to go up again.  The minimum was 23.126
seconds on Sept 30; by Oct 16 it was up to 23.135.  For
Nov 5 it was 23.149.  The satellite is getting low in the
southwest for the western U.S., so if you haven't seen it
yet, you only have a week or two.  Otherwise you'll have to
wait 'til next spring.

If there are any observers in Hawaii with binoculars or a
telescope, please contact me if you're interested in seeing
this near-geosynchronous satellite.  Its flashes will soon be
visible from the Hawaiian islands high in the south-southwest
during evening twilight.  Eastern islands may be able to
see it by the middle of next week.  --Rob