Superbird A observed in Tor

ROB MATSON (ROBERT.D.MATSON@cpmx.saic.com)
10 Mar 1998 19:14:14 -0800

Hello all,

Just went out to observe Superbird A (#20040) in exceedingly clear skies.
If it weren't for the nearly full moon only 11 degrees away, the flashes
would have been visible with the unaided eye.

I observed flashes with 8 x 56 binocs from 2:45 UT to 2:53 UT, 11 March
1998.  Peak flashes were right at the predicted time (around 2:48:30 UT).
1 minute either side of the peak, flashes were also visible on the half-
period.  Phase transition took place about the time of the peak, with the
previously dimmer odd half-flashes overtaking the brighter even =
half-flashes.
The even half-flashes subsequently dimmed so that only the odds were
visible.  This is the typical behavior that we've noticed in past years.

I did not have a stop-watch handy, so was not able to time flashes.
However, I do have a good estimate of the peak brightness -- about 3rd
magnitude.  Flashes were about twice as bright as the nearby 3.90-mag
star HD#083618, which was in the same field-of-view.

Of course, flash magnitudes are quite subjective, and estimates will vary
from individual to individual.  I've noticed that my estimates always =
seem
to be brighter than "the mean," so perhaps my eyes/brain have a fast
integration time!  ;-)   --Rob