Re: Spot 3 (93- 61 A)

Mir16609@aol.com
Mon, 19 Apr 1999 12:58:23 EDT

In a message dated 4/19/99 09:29:56 AM EDT, L.J.C.Barhorst@arcadis.nl writes:

> I only timed the brightest flashes. There were most of the time 3 fainter
>  flashes
>  inbetween the bright ones. This gives a period of 3.78 and 3.70 seconds

I've been meaning to ask this question to the BWGS observers for some time 
now.  For two objects I've had a problem in resolving how to report the 
observation.

In the case of SPOT 3 there are a multitude of flashes. The primary flash 
(IMO) occurs about every 13-15 seconds.  Last evening it was hazy and the 
primary flash is all that I could observe.  On other occasions I've seen a 
primary and a secondary flash only. Lately, on long, high elevation passes 
(with clear skies) I've counted as many as 33 flashes in 2.5 minutes 
including some very strange looking flashes.  How does one report these 
observations with some semblance of consistency?

Another popular object, Superbird A, has a primary and a secondary flash.  As 
it approaches the end of it's flash visibility window, the secondary flash 
fades to inv. about 2 minutes before the primary flash fades.  If I report 
the average flash period based on the total time it doesn't accurately 
reflect the true flash period.   If I truncate the PPAS report to include the 
time when both flashes were visible it doesn't capture the total visibility 
window.

Any advice?
 
>  These obs are not cosistend with eachother.
>  We need more obs!

Right now SPOT 3 is more interesting to observe than any of the tumbling 
Iridium satellites. 

Cheers
Don Gardner  39.1796 N, 76.8419 W, 34m ASL
Homepage: http://hometown.aol.com/mir16609/
Space Day - 6 May 1999; http://www.spaceday.com/