A protoplanetary nebula (1) in Cygnus, also known as CRL 2688. It was discovered at infrared wavelengths in 1974 by the US Air Force Cambridge Research Laboratories; a photograph of it taken by the Hubble Space Telescope in 1995 illustrates how a red giant star ejects matter at the end of its life. The Egg Nebula is approximately 3000 l.y. away.
Subjects: Astronomy and Astrophysics.