M30 - NGC 7099

Messier 30 (NGC 7099) is a globular cluster in the constellation Capricornus, located approximately 26,100 light-years from Earth. It contains several hundred thousand stars within a diameter of about 93 light-years and shines at an apparent magnitude of 7.2. M30 was discovered by Charles Messier on August 3, 1764. Like M15, M30 has undergone core collapse, a gravitational process where the cluster's core contracts to an exceptionally dense state. This makes M30's central region one of the densest stellar environments known, with stars packed thousands of times more closely together than in the Sun's neighborhood. Hubble Space Telescope observations have revealed that the core-collapse process has produced a significant population of blue straggler stars in the cluster's center. These blue stragglers, which appear hotter and younger than they should be for a cluster of M30's age, are thought to form through two mechanisms: direct collisions between stars in the overcrowded core, and mass transfer in close binary star systems. Researchers found two distinct populations of blue stragglers in M30, suggesting both mechanisms are at work. The cluster is estimated to be about 13 billion years old, among the oldest objects in our galaxy. For amateur observers, M30 can be somewhat challenging due to its relatively small apparent size and its location in a region of sky with few bright guide stars. Through binoculars it appears as a small fuzzy spot, while a telescope of 6 inches begins to resolve stars around the edges. The bright, unresolved core is a hallmark of core-collapsed clusters and is apparent even in modest telescopes.

Contains several hundred thousand stars within 93 light-years diameter at a distance of 26,100 light-years, estimated to be approximately 13 billion years old.