It has an apparent angular diameter of about 10 arcminutes.[9] Since it is 32,600 light-years (10,000 pc) away, this translates into a true (spatial) diameter of about 95 light-years.[9] It contains several hundred thousand stars, and ranks among the densest globular clusters in the Milky Way.[9] It is at more than twice the distance of the Galactic Center in regions considered the Galactic halo.
It hosts relatively many blue stragglers, stars that appear to be much younger than the cluster. It is thought these have lost part of their outer layers due to close encounters with other cluster members or perhaps from collisions between stars in the dense cluster. Images from the Hubble Space Telescope have shown pronounced districts of these stragglers in M80, suggesting the center of the cluster to have a very high capture and collision rate.[9]
On May 21, 1860, a nova was found in M80 that delivered a magnitude of +7.0 to telescopes, binoculars and astute eyes.[9] This variable star, given designation T Scorpii, reached an absolute magnitude of −8.5, briefly outshining the cluster.[9]
^Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.
^ abcdefg"Messier 80". SEDS Messier Database. Students for the Exploration and Development of Space. Archived from the original on January 14, 2022. Retrieved December 19, 2021.