Egg Nebula

CRL 2688 (also AFGL 2688 or 2688 RAFGL or egg - fog, English Egg Nebula ) is a bipolar proto- planetary nebula, about 3,000 light- years away. The object was discovered in 1975 as part of the Palomar Observatory Sky Survey.

The most striking structure of the nebula is a series of bright arcs and circles surrounding the central star. This itself is covered by a dense layer of gas and dust, a direct observation of the central star is therefore not possible. However, the light from the central star penetrates the thinner areas and lights up the outer gas regions, which cause so the arcs in the appearance.

CRL 2688 is among the nearest and best- studied bipolar proto- planetary nebulae.