A reflection of the Orion nebula
Date created: 1989-06-05
Tags: nebula, dust, Orion, reflection
A little over a degree north of the Orion nebula is a loose grouping of bright stars NGC 1973–75–77, seen at the top of this picture. Light from these stars is scattered by the dust, producing a reflection nebula that should be bluish. However, the plates that were used to make this image picture have been photographically enhanced and the colour balance unavoidably distorted, so that they appear a more greenish hue.
Nonetheless, this photograph is the first to show a new kind of nebula, whose light is not starlight reflected by dust, but the reflected glow of another nebula, seen as the yellowish fronds cross the centre of the image. These ghostly yellow shapes are the reflection of light from the Orion nebula itself, which is off the lower part of the picture. The light from the nebula is itself green light from oxygen and red light from hydrogen, so there is no blue light for the dust grains to scatter. Green light plus red light gives yellow light, hence the colour. All these objects are about 1350 light years distant, in the well known constellation of Orion
. Photograph made from plates taken in October 1979.
Top left is NE. Image width is about 27 arc min
Credit: David Malin
© Australian Astronomical Observatory