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Geostationary satellite compact trio

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#1 EJN



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Posted 21 June 2012 - 11:53 PM

I chanced upon a very compact group of 3 geostationary satellites
last night while observing Saturn in an 8" f/5 dob at 143x. Saturn
passed directly by the group, I noticed 2 "stars" which did not
move. When Saturn passed out of the field, I noticed a 3rd, fainter
one. I would estimate the 2 brighter ones at mag. 11, and the fainter
at mag. 12, they easily fit in the 1/3 degree field of view of the
eyepiece I was using. Watching stars drift through the field while
they remained motionless was almost...hypnotic.

Using Cal Sky, I identified them as XM-1, XM-2, & XM-4, of SiriusXM

As the night progressed, they slowly changed orientation with respect
to each other, doing a little "dance."

I was able to find them again tonight by setting up the scope in the
exact same spot, and using the TV antenna on the building I live in
as a reference point. At 10:16 pm, Saturn passed through the field
of view, exactly 4 minutes earlier than last night. They are repeating
the exact same "dance" as last night.

From my location, they are at alt. 34 degrees, azimuth 217 degrees.

#2 PaulZPA


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Posted 22 June 2012 - 12:23 PM

Interesting! I'll have to take a look for them.

#3 BSJ



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Posted 06 July 2012 - 10:44 AM

I saw them too! Only it was last night, 7-6-12 at 2230. AZ 228° 31' Alt +26° 01'

It's the first geostationary satellites I've seen. Was doing the same thing, observing Saturn. I had looked away from the eye piece for a moment. When I looked again I saw a moon moving. I literally thought to myself. "That's not a moon. It's a space sta… Satellite!" Que Star Wars memories. :roflmao:

I also noticed the two brighter ones first, and then the dimmer one. It was really quite eerie watching them with my Dob. Kept wanting to push on it to keep them in view, but didn’t need too. They stayed centered as everything else drifted by.

#4 Scott in NC

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Posted 07 July 2012 - 04:28 PM

Very cool! I've never seen any of these before (or at least if I have, I didn't realize what I was looking at).

#5 nytecam


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Posted 10 July 2012 - 05:19 PM

Fair easy to pick-up with a static camera on a tripod and exposure of a few minutes at most - geosats as points of light whilst stars trail :grin:

#6 b1gred



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Posted 15 July 2012 - 11:38 PM

Those 3 birds are in the same "box" in the geosync band. WildBlue/Viasat do that also, as do several other satellite operators. It takes some good coordination and accurate "flying" of the birds, but it's an efficiency operators love. The "box" is actually 3-dimensional about 600 miles E/W x 800 miles N/S by about 100 miles deep. The 2 in WildBlue's box do a little "figure-8" within the box daily.

It's pretty easy to find geosync satellites. Find out the elevation of the geosync band from your location, use the az/el function of your mount, but turn tracking off. Set the elevation for the band, then watch for a while, you'll start seeing "stars" that don't move with other that do behind them. The ones that don't move are the geosync birds, the ones moving are stars. There are a couple of web-sites that will give you the az/el for pretty much any geosync satellite based on your location.

#7 ido


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Posted 20 July 2012 - 04:45 AM

See link for a geo-sat movie


#8 ssandusky



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Posted 23 July 2012 - 09:13 PM

I would love to show these to my kids, what's the best way to find the XM satellites and other geostationary satellites like them?


#9 Starhawk


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Posted 21 October 2012 - 04:34 PM

Interesting indeed. Good work correlating them!


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