M12 - GUMBALL GLOBULAR

Messier 12 (NGC 6218) is a globular cluster in the constellation Ophiuchus, located approximately 15,700 light-years from Earth. It is similar in many respects to its close neighbor M10, lying only about 3 degrees away in the sky, and the two are often observed together during the same session. M12 contains several tens of thousands of stars within a diameter of about 75 light-years and shines at an apparent magnitude of 7.7. The cluster has a notably loose concentration for a globular cluster, classified as Class IX on the Shapley-Sawyer scale, which historically led some astronomers to wonder whether it might be a very dense open cluster rather than a true globular. However, its ancient age of approximately 12.7 billion years and the composition of its stars firmly place it in the globular cluster category. M12 was discovered by Charles Messier on May 30, 1764, making it the third of several Ophiuchus globulars he cataloged in rapid succession that spring. Research published in 2006 using Hubble Space Telescope data revealed that M12 has lost a remarkable number of low-mass stars due to tidal stripping by the Milky Way's gravitational field. The cluster may have lost as many as one million low-mass stars over its lifetime, meaning it was once significantly larger and more massive than it is today. This finding makes M12 an important case study in the long-term dynamical evolution of globular clusters. Through a small telescope, M12 appears as a moderately bright, somewhat granular ball of light, with stars beginning to resolve at around 4 to 6 inches of aperture.

Spans approximately 75 light-years in diameter at a distance of 15,700 light-years, containing tens of thousands of stars with a loose concentration.