Astronomers have found that certain white dwarf stars have atmospheres which are very rich in the rocky elements (such as silicon) which comprise Earth-like planets. A white dwarf is the core of an initially much larger star,whose outer layers have been lost when the star expanded to become a red giant. Astronomers suspect that as the star expands,it perturbs the orbits of any planets around it,perhaps leading to collisions. Repeated collisions grind down the planets into smaller and smaller pieces of rubble until the star,now a white dwarf,is surrounded by a disc of dust and hot gas. In this image we see such a disc,in which a few rocky fragments have yet to be absorbed | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Garlick, Mark |
Taille de l’image : | 5513 px × 3594 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |