Re: Did Anyone Else See This ? (fwd)

Bart De Pontieu (BDP@MPEPL)
Wed, 14 Aug 1996 18:52:02 +0100 (CET)

Larry Klaes forwarded a message from the astro-list:

>I saw something interesting once, and supposed it was some sort of 
>satellite, but never figured out what. Gazing upward from Big Bend park 
>in Texas one night in later December 1978 I saw a star-like white light 
>flash on and off about 5 times in rapid succession in about 1 second -- 
>like five white "dits", about the brightness of a 3'rd or 4'th magnitude 
>star. Then about a minute later another 5 flashes about 30 degrees to the 
>south of that, then another minute later yet another 5 flashes, a further 
>30 degrees or so to the south.
>Eric M. Bram
>gradivus@dreamscape.com

This sounds like one of the MIDAS-satellites, e.g. 63-14 A. I observed it in
August 1990 from Southern France with Kurt Jonckheere and others. It 
had a 'dominant' flash period of about 22 seconds. During most of this time
it is invisible to the naked eye. Only at the maxima is it bright enough to
be seen. The maxima can be multiple and very bright. I've seen flashes of
mag 0. Usually it's not as bright though, more like mag 6 or so.
Only if you're lucky will you see such bright flashes at the maxima, and
usually not even during the whole pass. This has to do with the orientation
of the rotation axis. Having never seen a picture of a MIDAS-satellite, I
don't know what causes the multiple flashes.

I've also seen other MIDAS-satellites (62-10 A and 63-30 A) come to mind,
and I think one of them has a flash period of about 1 minute. I've seen the
"bright flashing" behaviour in many of them, so it wouldn't surprise me if
Mr. Bram saw a MIDAS.

Cheers,
     Bart
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Bart De Pontieu --  Max-Planck-Institute for extraterrestrial Physics, Garching
bdp@mpe-garching.mpg.de  --      http://www.rzg.mpg.de/~bdp/satintro.html
Join us at Eurosom 2, Oct 19/20 1996 -- http://www.rzg.mpg.de/~bdp/eurosom.html
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           "PULLLL THE STRRRRING" -- Bela Lugosi in 'Glen or Glenda'
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