constellation of Sagittarius tagged posts

This sparkling burst of stars is Messier 75. It is a globular cluster: a spherical collection of stars bound together by gravity. Clusters like this orbit around galaxies and typically reside in their outer and less-crowded areas, gathering to form dense communities in the galactic suburbs.

Messier 75 lies in our Milky Way galaxy in the constellation of Sagittarius (the Archer), around 67,000 light-years away from Earth. The majority of the cluster’s stars, about 400,000 in total, are found in its core; it is one of the most densely populated clusters ever found, with a phenomenal luminosity of some 180,000 times that of the Sun...

An infrared and multi-wavelength image of the Central Molecular Zone in the Milky Way. Dense gas is shown in red, and warm and cold dust in green and blue respectively. Several key objects in the region are labeled, along with a set of embedded young stellar clusters seen at 24 microns. Credit: C. Battersby

The center of our Milky Way galaxy lies ~27,000 light-years away in the direction of the constellation of Sagittarius. At its core is a black hole ~4 million solar masses in size. Around the black hole is a donut-shaped structure about 8 light-years across that rings the inner volume of neutral gas and thousands of individual stars. Around that, stretching out to ~700 light-years, is a dense zone of activity called the Central Molecular Zone (CMZ)...