The center of the geoflares is at the Sun's declination, so it currently moves north. But to have the operational geosats a degree further north, you must travel six degrees south on the Earth's surface. Also note that the center of the Earth's shadow is at the anti-solar right ascension at local midnight, but at the opposite declination of the Sun! It is offset by the observers latitude, and also by the time of night. It moves < -00:10/hour in R.A. Also note that some geos (including XM-1/2?) have booster reflectors (at 60 deg angles?) causing extra flares 3-4 hours before/after expected maximum. Sun at 22:46 Latitude: 0 0 0 40 40 40 60 60 60 -7.8 Time 20:00 23:00 24:00 20:00 23:00 24:00 20:00 23:00 24:00 Shadow radius: 9.36 10.13 10.19 9.02 9.73 9.79 8.65 9.31 9.36 Declination offset: 0.00 0.00 0.00 -5.80 -6.25 -6.29 -7.50 -8.06 -8.11 RA offset: 00:32 00:10 00:00 00:23 00:07 00:00 00:14 00:04 00:00 Declination: 7.80 7.80 7.80 2.00 1.55 1.51 0.30 -0.26 -0.31 RA: 11:18 10:56 10:46 11:09 10:53 10:46 11:00 10:50 10:46 Excel file available on request. ----- Original Message ----- ... > Question: What do you believe the > geographic extent of the visibility of this event? And > which way does it move night after night - north or > south? > ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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