Gegenschein Observed from La Silla, Chile
February 10, 2023
Photographer: Zdenek Bardon
Summary Author: Zdenek Bardon: Jim Foster
During an observing session from the ESO Observatory in Chile one night this past November, in addition to various nebulae and star clusters, I also captured a patch of light, at center, called the Gegenschein or counterglow. Particles of dust and ice in the path of Earth’s orbit around the Sun scatter sunlight both forwards and backwards, depending upon their size. The backward scattered light is scattered (by smaller particles) with reduced intensity, so the resulting dim glow is only visible (to the naked eye) in extremely dark skies -- seen at the point in the night sky that’s opposite of the Sun (antisolar point). As with nearly all faint objects, you’ll have better luck viewing it if you use averted vision. Photo taken on the night of November 27, 2022.
Photo details: Nikon D810Da camera with ZEISS Otus 1.4/55 lens; stack of 27 images, each with an exposure of 60 seconds.
La Silla, Chile Coordinates: -29.2612 -70.7313
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Nighttime Arcs Visible from Dark Skies