Not quite - because the atmosphere refracts rays from (below) the horizon by about 0.5 degrees. So equatorial regions get about 2+2 minutes in excess of the 12 h. Higher latitudes get more, because the Sun approaches the horizon in increasingly shallower angles. At about +59.3 lat., with Sun at +23.45 deg, these 2 minutes become 6m15s around sunset at HourAngle 9h14m (Sun down for 5h32m). The factor is cos(h)/sin(H.A.)/cos(decl)/cos(lat) Taking the time for twilight instead, this extra daylight is 12/24/36 times longer, ie I hardly get any time after civil twilight. Thus, I hardly see observe satellites for two months. >> >>Last night I was talking to a friend and we were wondering whether the >>average amount of daylight hours that any given location on the earth >>gets over the course of the year would be the same. >> ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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