Ron, I forgot to include a note that as Kevin (and others) have observed, flares can be seen many degrees (ie weeks) from predicted pos (time). Anyway, theoretical optimum at 40N today, with Sun at 22:46 -7.8 d you (they) will be close to the shadow circle of 9.29 deg radius, centered at 10:46 +(7.8-6.29=)1.51 decl. at midnight. Your (their) Clarke belt is at -6.29, but the shadow circle extends down to (1.51-9.29=) -7.78 degrees, so the flaring geos will enter shadow some degrees west of 10:46 -7.78 (exit a few deg E), but most will probably be flaring at these points. Early in the evening RA will be around 11:05, decl. around -7.3 And you can probably see flares for another week or two. ----- Original Message ----- > Bjorn, I could not tell what these charts mean. Is it too late > to observe these flares at 39 deg N? > >>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 > ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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