Yesterday I communicated observations of MUOS 5 (2016-041A) in GTO: http://www.satobs.org/seesat/Jul-2016/0014.html I noted in my report that it showed a "a marked brightness variation". Imagery of that brightness variation is here: http://sattrackcam.blogspot.nl/2016/07/tracking-muos-5.html By looking through my image series from Jul 4-5, I found a periodicity of ~5.0 minutes peak-to-peak. Peak brightness I estimate to be in the order of mag +8 to +9. The brief peaks are short and somewhat variable in duration: it rises and fades in less than 30 seconds to less than ~1 minute. During minima, the satellite was invisible (note: observations were done in a light-polluted sky with the satellite at only 14-16 degrees above the horizon, and variable sky conditions) Approximate times of brightness peaks (accurate to ~30 seconds), from imagery with a 1.4/85mm lens and exposures of 10 to 15 seconds (depending on conditions): TIME (UT, July 4-5) 23:40:45 23:45:50 23:51:00 [break from cloud field] 00:10:55 [break from cloud field] 00:25:55 00:30:40 00:35:55 00:40:30 00:45:55 The ~5.0 minute periodicity is well discernable. - Marco ----- Dr Marco Langbroek - SatTrackCam Leiden, the Netherlands. e-mail: sattrackcam_at_langbroek.org Cospar 4353 (Leiden): 52.15412 N, 4.49081 E (WGS84), +0 m ASL Station (b)log: http://sattrackcam.blogspot.com Twitter: _at_Marco_Langbroek ----- _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Thu Jul 07 2016 - 08:19:31 UTC
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