In astronomy , reflection nebulae are clouds of interstellar dust which might reflect the light of a nearby star or stars. The energy from the nearby stars is insufficient to ionize the gas of the nebula to create an emission nebula , but is enough to give sufficient scattering to make the dust visible. Thus, the frequency spectrum shown by reflection nebulae is similar to that of the illuminating stars. Among the microscopic particles responsible for the scattering are carbon compounds (e. g. diamond dust) and compounds of other elements such as iron and nickel. The latter two are often aligned with the galactic magnetic field and cause the scattered light to be slightly polarized .
4-409: The Ghost Nebula (designated Sh2-136 , VdB 141 ) is a reflection nebula located in the constellation Cepheus . It lies near the cluster NGC 7023 . Looking at the adjacent image, the nebula's name is easily understood. The Ghost Nebula is referred to as a globule (catalogued CB230 ) and over 2 light-years across. There are several stars embedded, whose reflected light make the nebula appear
8-647: A yellowish-brown colour. This nebula-related article is a stub . You can help Misplaced Pages by expanding it . Reflection nebula Analyzing the spectrum of the nebula associated with the star Merope in the Pleiades , Vesto Slipher concluded in 1912 that the source of its light is most likely the star itself, and that the nebula reflects light from the star (and that of the star Alcyone ). Calculations by Ejnar Hertzsprung in 1913 lend credence to that hypothesis. Edwin Hubble further distinguished between
12-437: The emission and reflection nebulae in 1922. Reflection nebula are usually blue because the scattering is more efficient for blue light than red (this is the same scattering process that gives us blue skies and red sunsets). Reflection nebulae and emission nebulae are often seen together and are sometimes both referred to as diffuse nebulae . Some 500 reflection nebulae are known. A blue reflection nebula can also be seen in
16-476: The same area of the sky as the Trifid Nebula . The supergiant star Antares , which is very red ( spectral class M1), is surrounded by a large, yellow reflection nebula. Reflection nebulae may also be the site of star formation . In 1922, Edwin Hubble published the result of his investigations on bright nebulae . One part of this work is the Hubble luminosity law for reflection nebulae, which makes
#487512