My observations of the same pass, and the pass later that night confirm Marco's observations. I've posted some pictures, a video and some graphs on this twitter thread: https://twitter.com/cgbassa/status/1133827825113423872 The main conclusions are that the Starlink satellites flare regularly, but vary between +6 and +4 magnitude. However, it seems they can also reach negative magnitudes, as on the first pass some of the trailers, which passed higher in the sky, reached magnitude -1. In video observations of the second pass (23:21 to 23:45UTC) I was able to see all 64 objects which have been catalogued by CSpOC, and the four objects that they classified as debris clearly stood out in their optical behaviour. Those four objects showed four brief flares, only to decrease to magnitude +7 or fainter, whereas the 60 payload objects were all either constant near magnitude +6 or flared to +4. Furthermore, the four debris objects matched the CSpOC predictions, whereas none of the payload objects did. This suggests that they are actively adjusting their orbits and that all of them are, in some form, operational. For these observations I've been experimenting with an all sky camera, based on an 6 megapixel ZWO ASI178MC CCD camera and a 2.5mm F/1.2 lens (this is supplied with the camera). This lens provides a 150 degree field-of-view (almost to the horizon). With 15s exposures I can just make out M13 and the ~+7 mag flanking stars when they are near zenith. This setup picks up many of the bright satellites, several of them from classfd.tle. It is also very useful to document flaring behaviour of many satellites. I need to play a bit with software to see if difference imaging can pick out the satellites and if the astrometry can be determined accurately enough for identification/position measurements. Regards, Cees _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Wed May 29 2019 - 15:53:49 UTC
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