Gorizont 23 & other high altitude flashing satellites

Jason Hatton (jason.hatton@etss.u-strasbg.fr)
Wed, 13 May 1998 19:20:10 +0000

Hi SeeSater's,
                Thanks to a spell of mainly clear skies over the last
few days I've been able to measure the flash period of the bright
geoflasher Gorizont 23 on a daily basis;

91- 46 A 98-05-07 21:20      JPH 599.2 0.2  12 49.93  A'A' mag+5->inv
91- 46 A 98-05-08 21:10:53.8 JPH 998.9 0.1  20 49.94  A'A' mag+5.7->inv
91- 46 A 98-05-09 22:15      JPH1448.4 0.1  29 49.95  A'A' mag+6->inv
91- 46 A 98-05-10 22:24:30   JPH 999.2 0.1  20 49.96  A'A'      
91- 46 A 98-05-11 20:48:49   JPH1548.7 0.1  31 49.956 A'A'
91- 46 A 98-05-12 21:05:48   JPH1748.9 0.1  35 49.968 A'A'

These observations show that the flash period appears to have increased
over the last few days, although maybe not at a constant rate;
 
Kurt Jonhkeere's obs.
98-05-04 = 49.908 +/- 0.004
My obs.
98-05-07 = 49.933 +/- 0.016
98-05-08 = 49.945 +/- 0.005
98-05-09 = 49.945 +/- 0.007
98-05-10 = 49.960 +/- 0.005
98-05-11 = 49.956 +/- 0.003
98-05-12 = 49.968 +/- 0.003

A few other interesting recent observations concerning Centaur rockets.
I discovered a new flashing Centaur, the Atlas I Galaxy 5 rocket
(92-013B). Flashing with a period of 18 sec, with bright, mag +7 flashes
at a range of over 30,000km;

92- 13 B 98-05-10 20:56:14.7 JPH 671.0 0.2  37 18.13  F'F' vm mag+7->inv

Most other Atlas Centaurs & Atlas I Centaur's seem to flash brightly
enough to be spotted out to maximum range (approx. 37,000km), such as
the ATS-5 rocket flashing as brightly as mag +8. One of the prettiest is
the Intelsat 4-4 rocket (72-003B) with a rapid flash period of 1.526s.
This is perhaps a nice object for a star party, when EGP isn't visible,
since at moderate ranges it is relatively bright moves quite slowly
though a telescopic field of view. At the other extreme is the Atlas
Centaur 75-042B which was quite a challenge to observe & follow,
invisible except for relatively bright flashes every 209s...

Best wishes & clear skies,

Jason

-- 
Jason P Hatton
INSERM U311
ETS Strasbourg
67065 Strasbourg Cedex
France


48.538N / 7.731E / 143m