# Re: unid flashing geosynch

From: Mike McCants (mmccants@io.com)
Date: Mon Sep 20 2004 - 12:00:44 EDT

• Next message: Tony Beresford: "Indian Geolaunch"

```Ed Cannon posted:

>Last night looking for Gorizont 29, I saw an unid flashing
>geosynch.  The brightest maxima were +4.5.  The flash
>period was about 42 or a multiple of that.

Based on positional observations from Sept. 20 04:43 to 05:52 UT
I have derived the following circular orbit:

Unknown 040920
1 90022U 04764A   04264.19896990 0.00000000  00000-0  00000-0 0    04
2 90022   9.7600  77.0000 0001000 223.0000   0.0000  1.06382000    09

This is quite low for a circular graveyard orbit.  Alternatives are
that the object was near perigee with a non-zero eccentricity:

1 90022U 04764A   04264.19898147 0.00000000  00000-0  00000-0 0    00
2 90022   9.7900  77.0000 0100000 223.0000   0.0000  1.04182000    08

1 90022U 04764A   04264.19894675 0.00000000  00000-0  00000-0 0    02
2 90022   9.8100  77.0000 0150000 223.0000   0.0000  1.02982000    02

1 90022U 04764A   04264.19899305 0.00000000  00000-0  00000-0 0    07
2 90022   9.8300  77.0000 0200000 223.0000   0.0000  1.01982000    09

There are many other solutions with appropriate values of eccentricity,
argument of perigee, and mean motion.

I can even generate a synchronous orbit with a high enough eccentricity:

1 90022U 04764A   04264.19903934 0.00000000  00000-0  00000-0 0    01
2 90022   9.8400  77.0000 0290000 223.0000   0.0000  1.00270000    08

But I am puzzled by an inclination of 10 degrees with a node at 77 degrees.
I cannot generate an elset like this using any reasonable starting elset
by applying lunar and solar perturbations.  A typical orbit with a 10
degree inclination has its node about 43 degrees.  A typical orbit with
a node near 77 degrees has an inclination of only 5 degrees.  Because of the
place in the orbit where the observations were made, the inclination
and node are reasonably accurate.

The brightest flashes last night were about RA 19Hr 15Mn, Dec -12 degrees.
The observed pattern was 3 bright flashes over 85 seconds followed by
a gap when 4 flashes were not seen, followed by another 3 bright flashes
about 210 seconds after the preceding set.  Later, only flashes to magnitude
9 or 10 were seen in the 8 inch.

Mike McCants
Austin, TX

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