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