Egg Nebula, Hubble Space Telescope image. This is a planetary nebula. Here, concentric shells of gas and dust have been ejected by a star near the end of its life. The layered effect is due to variations in the rate of mass ejection with time. The shells extend over a tenth of a light year from the star. The central star is hidden by the dark vertical dust lane (centre). The colours were assigned using polarizing filters to distinguish between angles of reflection. The Egg Nebula is 3000 light years away in the constellation Cygnus. Image obtained in 2002 by Hubble's Advanced Camera for Surveys.