Genealogy of stars
a cluster of galaxies has been found that looks bright in the x -rays region but contains only a single visible galaxy. A team led by M Hattori at the Max-Plank-Institut fur extraterrestrische Physik, Giessenbachstrasse, Germany, reports that it is the most distant cluster of galaxies in the x -rays region. The discovery may help understand formation of structures in the Universe (Nature , Vol 388, No 6638).
Structures in the Universe exist in diverse forms such as stars, galaxies of stars and clusters of galaxies. Clusters are the largest gravitationally bound objects that contain nearly 10,000 galaxies. They are divided into three classes