images

Planetary nebula Abell 21 in Gemini

by

R.Gendler/Novapix

Reference

a-nep98-02600

Date

2008-02-03

The Medusa Nebula (Abell 21 or PK205+14.1) is a very old planetary nebula located about 1500 light years away in the constellation of Gemini. It spans approximately 4 light years across. The burned out stellar cinder known as a white dwarf can be seen glowing blue (by virtue of its emitted heat) in the center of the nebula complex.