Gorizont 23 flash period 1% decrease

Mike McCants (mikem@fc.net)
Thu, 7 Aug 1997 08:58:19 -0500 (CDT)

As Ed Cannon described, we observed flashes from Gorizont 23
for over 110 minutes last night.  The first timed flash was
at 2:33:00.9 UT on August 7, 1997.  The last timed flash
was 1:44:51.5 after that.  Dividing 6291.5 seconds by 119 cycles
gives a period of 52.870 seconds.  This compares to an observed
period of 53.442 last May 17 (May 18 UT).  Very interesting.

The flashes seemed brighter to me at 4:10UT than at 2:33UT, but
I was looking through my 8" at 100x.  Gorizont 23 seemed to be on
my limit of observability (about mag 13) most of the cycle, but
brief brightenings to mag 12 (at 40.0 seconds) and mag 11.5
(at 47.4 seconds) were repeatedly observed.  40.0 seconds is
about 0.75 of a cycle and 47.4 seconds is about 0.90 of a cycle.

>Observing location was BCRC Austin, Texas, USA, 30.315N, 97.866W, 280m.

For Gorizont 23, the altitude was 48 and the azimuth was 148.

Mike McCants