astronomy

We all take stars for granted, they are just there many are bright enough to be seen from the city. There are people who specialize in Spectography (Spectrography is the technique of recording and analyzing the spectrum of light or other radiation emitted or absorbed by materials. It is used in...

Clusters both Open and Globular. From the Wiki: A star cluster is a group of stars, predominantly within a galaxy,[citation needed] held together by self-gravitation. Two main types of star clusters can be distinguished: globular clusters, tight groups of ten thousand to millions of old stars...