[ATMoB-discuss] geostationary satellite observation

[Bert Halstead]

Sunday night while observing M11 from my parents' place on the south 
shore of Long Island I had an experience that I figure many of you must 
have had, but I haven't ever read any discussion of it, so I thought I'd 
post a brief report.

While viewing M11 at 220x I saw a moving object, about 11th magnitude, 
enter the field.  It had the slow, smooth motion that immediately made 
me think "satellite" but then I realized that if this was a 
garden-variety satellite, at 220x it would have zoomed through the field 
at warp speed.  After puzzling over this for a moment, I thought, huh, 
maybe it's a satellite in a geosynchronous orbit.  So I turned off my 
clock drive and, sure enough, the satellite became stationary in the 
field while all the stars started flowing by at the same rate in the 
opposite direction!  It was cute enough that I watched it for several 
minutes before moving on.

Since my understanding is that geostationary satellites all travel in 
nearly the same orbit, I guess that if you observe M11 (or any other 
object at the same declination) from that latitude it won't be that 
uncommon to see a geostationary satellite drift across.  I wonder how 
numerous those satellites are over our part of the world.  I found a 
couple of informative Web pages at

http://satobs.org/geosats.html
http://www.planet4589.org/space/book/LOGS/logindex/geo.html

but I still didn't get an exact answer to the question.  However, it 
looks like there probably are dozens of them, although magnitude 11 may 
be brighter than average for them.

-Bert