Strobes in the sky!

Ed Cannon (ecannon@mail.utexas.edu)
Sun, 19 Apr 1998 15:44:54 -0500

Last night Sue Worden, Mike McCants and I went to a star party
with the darkest sky I've been under since I got into watching
satellites.  It was under-attended, probably because it was 
mostly cloudy all day (and it's also about 65 miles/104 km NW 
of Mike's house).  Only the three of us and two other astronomers 
with 16-inch telescopes were there.  The location was 30.884N, 
98.430W.

Perhaps the most spectacular observation of the evening was an 
unexpected display from an object in a highly eccentric orbit.  
Mike said, "Oh, we almost forgot Raduga 33."  (It's #23794, 
96-10A, a known flasher.)  He read the alt-az, which were 
somewhere in the general vicinity of Ursa Major, so I looked 
that way, and in a couple of seconds there was an surprising, 
bright one-power flash there.  There were several more such 
flashes, and Mike confirmed that it was indeed Raduga 33, at a 
range of over 4,800 km/3,000 miles.  Afterwards we discussed the 
magnitude and perhaps reached a consensus of +1, with a range of 
maybe zero to +2 being mentioned.  So maybe that's what caused 
the flash in the NE that someone reported a week or two ago.  
(I also got to see Raduga 33 briefly through one of the 16-inch 
telescopes, but I wasn't quite able to read the insignia!)

Another strobe-in-the-sky was Superbird A, with easy one-power
flashes around 3:59 to 4:00 UTC on April 19.  Another was 
Iridium 27 with a couple of one-power flashes towards the end of
its pass; we missed most of its pass while looking at something 
else.  We also saw a few bright one-power flashes from the 
COMETS H-2 rocket (now numbered 25176, 98-11B), at a range of 
over 1,900 km/1,200 miles.

The unidentified geosynch (pseudo-cat. # 98001) is still 
flashing to about mag. +6, but last night it and Superbird A both 
fit easily within one binocular field!

A few other notable observations I wrote down:

Mir VDU (25294, 86-17MQ) reached one-power visibility from our
dark-sky site.  (Mir itself also made a nice near-zenith pass.)

STS-90 (25297, 98-22A) made a one-power pass low in the SW 
(maybe our last opportunity to see it from here).

Cosmos 1703 (16262, 85-108A) made a very bright (+2) pass.

NOSS 0 rocket (05679, 71-110B) visible at one-power.

COMETS payload (25175, 98-11A) visible at one-power (at range
of 2,080 km/1,300 miles)!

Nice one-binocular-field view of all three NOSS 2-2 objects
(91-76C, D, and E).

There was an UNID one-power (reached +2) object that ascended 
from below Polaris (alt. about 10 to 15 deg.) to beside it 
(to its left a few degrees) that I haven't identified yet 
using molczan.tle and eccen.tle.  I wrote down only "10:22" 
(3:22 UTC on 19 April).

Ed Cannon
ecannon@mail.utexas.edu
Austin, Texas, USA