As Simone Corbellini reported, experts seeking to restore command and control of Phobos-Grunt are interested to know whether it is stable or rotating (tumbling): http://satobs.org/seesat/Nov-2011/0103.html Brad Young observed it on Nov 10, about 11:33 UTC, and reported it steady in brightness, which indicates little or no rotation: http://satobs.org/seesat/Nov-2011/0101.html There has not been a formal request for observations by the public, but additional observations using the various methods available to us may be of value. Due to its low altitude, the object is only visible during narrow ranges of latitude. Northern hemisphere observers between roughly 20 N and 40 N have morning twilight visibility. Southern hemisphere observers between roughly 7 S and 25 S have evening twilight visibility. The best observing conditions occur near the middle of the above ranges. Useful observations could take several forms: 1. Still camera exposures, showing the satellite's trail as a streak. If it is rotating, then there will be regular variations in the brightness of the streak. 2. Motion video. Follow the object for at least several minutes, to reveal whether there are regular variations. 3. Visual timing of maxima or minima (if any). This is the method that Brad used this morning. Instructions, including standard reporting format are here: http://www.satobs.org/tumble/flashpm.html Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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