Discovery
Edwin Hubble distinguished between the emission and reflection nebulae in 1922.
Reflection nebulae 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. Among the nicest of the reflection nebulae are those surrounding the stars of the Pleiades. A blue reflection nebula can also be seen in the same area of the sky as the Trifid Nebula. The giant star Antares, which is very red (spectral class M1), is surrounded by a large, red reflection nebula.
Reflection nebulae may also be the site of star formation.
Read more about this topic: Reflection Nebula
Famous quotes containing the word discovery:
“Next to the striking of fire and the discovery of the wheel, the greatest triumph of what we call civilization was the domestication of the human male.”
—Max Lerner (b. 1902)
“The virtues of society are vices of the saint. The terror of reform is the discovery that we must cast away our virtues, or what we have always esteemed such, into the same pit that has consumed our grosser vices.”
—Ralph Waldo Emerson (1803–1882)
“I have known no experience more distressing than the discovery that Negroes didn’t love me. Unutterable loneliness claimed me. I felt without roots, like a man without a country ...”
—Sarah Patton Boyle, U.S. civil rights activist and author. The Desegregated Heart, part 1, ch. 10 (1962)