Astronomy Picture of the Day

Explanation: Stars come in all different colors. The color of a star can indicate not only its surface temperature, but also its type. Most stars in the above Sagittarius Star Cloud are orange or red and relatively faint, as our Sun would appear. The blue and green stars are relatively hot, many being relatively young and massive. The bright red stars are relatively cool, many being Red Giants, bloated stars once similar to our Sun that have entered a more advanced stage of evolution. The Sagittarius Star Cloud appears as a window of jewels though the dark dust visible towards the center of our Galaxy, and houses some of the oldest stars known.