Recently Launched Cosmos Objects, etc.

Eric Vondra (evondra@usaor.net)
Wed, 01 Jul 1998 12:03:17 -0400

My observations early on 7/1 (UT) included Cosmos 2352
though 2357. These were interesting for a variety of
reasons. In chronological (pass) order:

Cosmos 2357 (98 036F, #25368) - Steady at 5.0 mag for about
half a minute after coming out of shadow (which surprised me
given its 2000+ km altitude), then an abrupt drop in
brighness to 8.0 mag, where it remained and slowly faded as
it moved north.

Cosmos 2356 (98 036E, #25367) - Started at 8.0 mag, then
slowly brightened to 7.0, back to 8.0, then slowly
brightened to 6.0, then faded to 9.0.

Cosmos 2353 (98 036B, #25364) - Started at 8.0 mag, then
brightened to 2.5 mag for 20 seconds at culmination, then
faded to 8.0 and slowly faded as it moved north.

(By now I'm thinking I should check out the rest of the
objects from this launch!)

Cosmos 2355 (98 036D, #25366) - 8.0 mag, steady. 30 seconds
behind Cosmos 2353.

Cosmos 2352 Tsyklon rocket (98 036G, #25369) - Steady at 6.5
mag. However, noticed  an 8.5 mag object on same track but
about 1/3 degree west and a degree behind. This object was
in a lower orbit, and overtook the rocket body as the pass
progressed, ending up about 5 degrees ahead by the end of
the pass, but still on the same orbit track. (They made a
nice pass right through the "Coathanger" asterism.)

Cosmos 2354 (98 036C, #25365) - Steady at 7.5 mag.

Cosmos 2352 (98 036A, #25363) - Steady at 7.5 mag.

Other observations of note included:

- my first unaided-eye observation of EGP (86 061A, #16908),
which made a beautiful overhead pass. I could just barely
make out some of the flashes with averted vision. My
location has moderate/light light pollution (but it was
exceptionally clear),

-a -5.0 flare from Iridium 73 (98 032C, #25344) caught by
accident as I was watching Lacrosse 2 (91 017A, #7615),

- Iridium 70 (98 032A, #25342) at 6.0 mag, flared to 3.5,
faded to 5.0, then flared to 2.5,

- Pegsat (90 028A, #20546), which gradually increased in
brightness from 6.0 mag to a quick flash around 5.0 mag,
then dropped back and repeated (didn't time it--20 seconds
or so), then stayed steady at 6.0. It was very fast, but
most surprisingly, it went into shadow 25 degrees further
along its track than predicted by SatSpy 2.5 using:

Pegsat           3.0  1.1  0.0  7.4 d
1 20546U 90028A   98169.21409770  .00041786  00000-0
35538-3 0  3233
2 20546  94.1168  53.0204 0035294  35.2508 325.1077
15.68620545458507

-USA 86 (92 083A, #22251). Caught this one on a perigee
pass, mag 3.0. It brightened slightly a couple of times. It
was 5 degrees east of track and about 3 minutes early using:

USA 86          15.0  3.0  0.0  5.1 v
1 22251U 92 83  A 98137.92278468  .00001300  00000-0
86670-4 0    06
2 22251  97.7482 210.2627 0420996 216.3025 143.6974
14.55581293    07

One more note: Nimbus 4 r CD (70 025CD, #4719) used to be a
nice 1 second flasher, but is no longer flashing. Observed
it steady at 6.0 mag on 6/24. It's period had started
increasing as of late summer 1997, which is when I had last
observed it.

Excuse the lengthiness of this post- I haven't had a clear
night in a while!

Eric Vondra
Wampum, PA, USA
40.8538N 80.3292W