Geosynch Flasher seen in Colorado

Ron Lee (
Sat, 28 Sep 1996 22:13:38 -0600 (MDT)

After a cloudy attempt last night, my attempt to
view Superbird A (#20040) was successful tonight
(28 sep 96 local).

Again using Rob Matson's Skymap to set up by a reference
star, I shut down the clock drive on the 8" telescope and
started observing by 850 PM MDT (250 UT 29 sep 96).

At about 9:13:30 PM (3:13:30 UT), I observed faint flashes
of about 9th magnitude.  I was unable to get a flash period
due to moonlight glare and the fact that the satellite was
only visible about 2 minutes.  Not very exciting visually.

Then about 9:24 PM MDT (3:24 UT), the flashes resumed.  The 
first period was 23.4 seconds.  Note that this was going from 
BRIGHT flash to Faint flash back to BRIGHT flash.  The same
period was observed on one additional attempt.

It exhibited a definite ramp up and down in brightness, eventually
becoming visible in binoculars.  Estimated max magnitude was 3-4.
It should have been visible to naked eye without glare from
nearly full moon.  

Last flash seen was around 9:37:15 PM MDT (3:37:15 UT 29 sep).

It may have been visible for a short period around 9:48 PM but that
was not a definite sighting.

The period of max brightness was very beautiful.  Definitely worth
the effort to see.

I still do not understand why an event that is probably tied to 
specific viewer-satellite-sun orientation should occur at the same
time for viewers about 16 degrees apart in longitude.  I am at 104.56
degrees west, latitude 38.9478, 2073 meters, (UT-6).

If someone can educate me on why this happens, please do so.

Ron Lee