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Gegenschein and Light-bridge

Date:21.08.04 Time:23:56 UT Exposure:40 min
Field of View:circular 180o Emulsion: Kodak E200 Filter:none
Instrument:f=8mm 1/4.0 Place:Hakos, Namibia Observer:Till Credner
Notes to the data

This circular all-sky view shows the milky way overexposed along the western horizon (right hand side) and a fainter glowing band all across the field. The path of this band is all along the ecliptic with a brighter patch in the constellation of Capricornus. The ecliptic is (with minor deviation) the plane of our solar system. Not only the planets can be found in this plane, also a wealth of dust particles which scatter the light of the sun. Especially in the antisolar direction, which is the constellation of Capricornus in August, the light is quite bright due to favoured backscattering in the angle of 180 degrees. This is called the Gegenschein, the german expression for counter-glow. The faint band is called Light-bridge since it connects the Gegenschein with the brighter zodiacal light in the evening and morning.

You need a very dark and transparent sky for naked-eye observation of the Gegenschein and an even better sky for detection of the Light-bridge (I could not see the Light-bridge by naked eye even under the excellent namibian sky).

See also:
Images of the Zodiacal Light
James et al., "The morphology and brightness of the zodiacal light and gegenschein", 1997MNRAS.288.1022J
Leinert et al., "The 1997 reference of diffuse night sky brightness", 1998A&AS..127....1L