Re: Gorizont 24

Jason Hatton (
Fri, 30 Apr 1999 10:05:45 +0200 (MET DST)

>Hi Jason,
>> Rerunning the passes of the TDRS7-Rk & Gorizont 24 through Skymap appears
>> to confirm this identification. (my initial postion measurement was in
>> error in declination, I forgot about the field inversion in the
>> telescope....).
>I would have IDed your sat as Gorizont 24 except that, as you indicated,
>the declination was a bad match.
>> There are no reported flash measurements for Gorizont 24 in the PPAS
>> database, so this might be a new geoflasher.
>My report may not have made it into the database yet.  I discovered it
>on March 25 while timing nearby Gorizont 23 flashes.  Flash period
>then was 89.846 +/- .011 seconds.  Here is an excerpt from my
>Seesat post on 3/25:

I remember seeing this post now, but hadn't added the object to my
observing lists. At least this confirms that Gorizont 24 is also easily
observable from Europe also.

Yesterday evening I ran a search using Mike McCants "Findsat" programme,
then plotted the tracks of satellites which were in the vicinity through
Skymap.   Now I have a full explaination of what I saw. The first two
flashes did in-fact appear south of the TDRS-7Rk track, so this fits with
Gorizont 24's position. However at the same time a debris object
670001AE/13910 (not a know flasher) was passing along a WNW->ESE track just
to the north of the TDRS7-Rk, so the third flash probably came from this
object which led me to beileve that the UNID was moving in a northerly
direction (it wasn't case of me mixing up the field orientation after all).
As a result I kept this spot fixed in the field of view & missed any
further flashes from Gorizont 24 as it was outside of the field of view of
my telescope.

I still haven't been able to make any follow up observations to to adverse
observing conditions. However, both Gorizont 23 & Gorizont 24 are now well
placed for European observers. For those observers who have never seen a
geosynchronous satellites both of these objects are potentially visible in
binoculars, flashing up to mag +5 at least. Gorizont 23 flash period is
about 50s, whilst as Rob Matson indicates Gorizont 24 is flashing every 90s.

Here are recent elements for both of these objects;
1 21533U 91046A   99116.36469887  .00000017  00000-0  10000-3 0  1445
2 21533   4.5603  65.0425 0004945 103.1699 256.8504  0.98905113 22670
1 21759U 91074A   99113.45341774 -.00000018  00000-0  10000-3 0  8110
2 21759   4.2503  65.4330 0014683   2.6538 357.3166  0.98441951 27413

Best wishes & clear skies,


P.S. <Off topic> I'm thinking of adding encoders & "digital setting
circles" to my dobsonian telescope (eg. like the Meade Magellan 1 system).
If anybody has any experience with this kind of setup could you give me
some suggestions (e-mail me directly, not to the list the list) on how best
to impliment this.

Jason Hatton
Hopital de l'Archet
Rte St. Antoine de Ginestiere
BP 79, 06202 Nice Cedex 03


email :

 43.667N, 7.223E, Alt 30M