Bill Purcell wrote: >I just watched the HST as it passed over Houston, and was treated to an >unexpected double flare! At approx. 21:34:00, it flared to about -2, >then at 21:35:30, it flared again to about -4, the brightest I've ever >witnessed it ... quite a sight, indeed. I guess the solar panels were >aligned just right for my vantage point. Assuming that these times are Central Daylight Time on 2-JUL-05 and that the solar panels were pointing straight at the Sun the difference in their pointing to the ideal flare direction would have been 37° at 21:34 and 18° at 21:35:30. So it seems unlikely that the solar panels were responsible (does anybody know whether the HST solar panels are always pointing directly at the Sun?). I have seen the HST flare on a number of occasions (but never a double flare) and I think one prime candidate would be the flat back surface (where the prime mirror is located). This offers the exciting possiblity of figuring out where the HST was looking at when the flare occurred. Assuming your -4 flare at 21:35:30 was caused this way the back surface would have been pointing at RA 5h34m, Decl 18°44' and the HST observations done at the time would then be in the opposite direction of the sky. Does anybody know whether there is a website to find out where the HST was pointing at during that time to test this hypothesis? Gerhard HOLTKAMP Darmstadt, Germany ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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