Right Ascension	16 : 17.0 (h:m)
Declination	-22 : 59 (deg:m)
Distance	27.4 (kly)
Visual Brightness	7.3 (mag)
Apparent Dimension	8.9 (arc min)
Discovered by	Charles Messier January 4th 1781

M80 is a fine 8th mag globular. Its 9' angular diameter corresponds to roughly 72 light years linear dimension at its distance of 27,400 light years. Its appearance resembles very much that of a comet.

This dense stellar swarm contains several 100,000s of stars, held together by their mutual gravitational attraction. It is one of the densest globulars in our Milky Way Galaxy. As was found by astronomers from observations with the Hubble Space Telescope in 1999 in the visible and UV part of the electromagnetic spectrum, M80 contains a large number of so-called "Blue Stragglers" in its core, about twice as much as any other globular investigated with the HST. These stars are blue and bright stars which appear near the main-sequence of the Hertzsprung-Russell diagramm, and thus appear more massive and younger than the globular clusters age. The reason is very probably that these stars lost their cooler envelopes in close encounters with other stars. Their large number in M80 indicates an exceptionally high stellar collision rate in the core of this globular cluster.

Messier observed M80 on January 4th, 1781 "Nebula without a star in Scorpius,....." " This nebula is circular; the center is bright and resembles the nucleus of a small comet, surrounded by nebulosity. M Mechain saw it on 27 January 1781" Charles Messier from his catalogue

William Herschel was the first to resolve it (before 1785), and found it was "one of the richest and most compressed clusters of small stars I remember to have seen."

Courtesy www.seds.org