Various obs. Dec. 25-31
Ed Cannon (ecannon@mail.utexas.edu)
Wed, 31 Dec 1997 03:47:04 -0600
Mir
My parents, sister, and I all saw the same great 25 Dec (UTC) Mir pass
over San Antonio, Texas, that Robert Reeves already wrote about. My dad
and I were at his evening walk location, and my mother and sister were
at home.
Iridiums
All four of us saw a *fantastic* flare from Iridium 29 (#24944, 97-51A)
at about 01:14:30 on 28 Dec 1997 UTC. Rob Matson's Iridflar program
predicted -8, GSOC predicted -6. I don't know how I'd estimate it beyond
saying it was *definitely* a monster! (Has anyone tried to get an actual
instrumental measurement of the magnitude of one of these things?)
With respect to Iridium flare magnitude predictions, here are two others.
At about 12:45:17-18 on 27 Dec UTC, Iridium 31 flared to what I estimate
was at least as bright as Venus -- much brighter than predicted by either
Iridflar (mag. 0) or GSOC (-2). At about 01:08:24-25 on 29 Dec, Iridium
32 first flared to about the brightness of nearby Capella (alpha Auriga,
mag. 0). GSOC predicted -1, Iridflar predicted +1. Then after dimming
to about +3.5, at about 01:08:55 it flared again to +2!
An UNID observed northbound in Perseus at about 01:17:20 on 29 Dec appears
to have been Iridium 33 (#24946, 97-51C) "flaring" to about mag. +3.5 to
possibly +3.
Last (possible) Iridium -- at about 01:23:55 I saw a single, brief mag. +1
flash that I wrote down as being alt. 80, azi 280. I tried but failed to
catch anything around there in binoculars. Checking later for anything
that might possibly have been there, I got Iridium 27 (#24947, 97-51D) at
alt 75, azi 275 at that time! It's one of the non-functional ones, stuck
in a parking orbit. I wonder if it may be tumbling.
Lacrosse 2 -- one flash, to mag. zero, on 25 Dec.
Two in One Field
On 28 Dec, 00:41-42 UTC, Cosmos 1242 Rk (#12155, 81-8B) and Cosmos 1766
(#16881, 86-55A) traveled along together, separated by about two or three
degrees -- observed in 10x50 binocs. (Both were visible at one-power,
although C* 1766 was pretty faint.)
USA 132 Rk (#24877, 97-35B) reached at least mag. +2 on its pass 28 Dec,
00:53 UTC; it passed a few degrees above Polaris (alpha UMa) at 00:53:18.
Two Iridium Delta rockets -- #24970 (97-56F, twice) and #24874 (97-34F,
once) both reached at least mag. +1.5 and possibly +1.0. All three of
these passes were below 300 km. (190 miles) above the surface. I saw
both objects early 31 Dec (UTC) from outside my Austin apartment through
thin clouds; the #24970 pass (00:13-14) with the Sun at -7.5 degrees!
Finally, around 00:30-31 UTC on 27 Dec, my dad and I, during a walk,
stopped because I wanted to try to see the NEAR rocket (#23785, 96-8B,
predicted to decay on 8 Jan). My dad saw it, noted how fast it was
moving, pointed at it and described four or five maxima and minima --
while I tried but failed to see it. Maybe I'd better replace my
11-year-old glasses (still quite good but with quite a few scratches).
Ed Cannon
ecannon@mail.utexas.edu
Austin, Texas, USA