Du Bois that are considered autobiographical. Topics: Astronomy, Sun, Atmospheric Phenomena Civil Twilight TodayĬivil Twilight from 06:46-07:18 in the morning.Ĭivil Twilight from 17:03-17:35 in the evening.Published in 1940, Dusk of Dawn: An Essay Toward an Autobiography of a Race Concept is the second of four works by W. However, in locations around the poles that experience polar night during the winter months, the Sun may reach an angle of 12-18° below the horizon around midday, causing a short daily period of astronomical twilight, a temporary break from the complete and permanent darkness that envelops polar regions in the winter.Īstronomical twilight is a good time to observe and photograph northern and southern lights as well as other atmospheric phenomena like false dawn. Within the polar circles, the Sun does not set at all in the summer, so there is no twilight during that time of the year. In Europe, it covers much of Germany.Īn all-night period of astronomical twilight does not constitute a white night, which requires the Sun to remain less than 6 degrees below the horizon all night, causing civil twilight from sunset to sunrise. In the northern hemisphere, this roughly correlates with the area between locations just south of the US-Canadian border and Canadian cities like Edmonton, Alberta. The area experiencing all-night astronomical twilight around the summer solstice lies between about 48☃3′ and 54☃3′ North and South. Timing of the twilight phases where you are Twilight Around the PolesĪt high latitudes and around the summer solstice, the Sun does not move lower than 18° below the horizon, so twilight can last from sunset to sunrise.
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