Palomar 12 is a globular cluster in the constellation Capricornus, and is a member of the Palomar Globular Clusters group.
First discovered on the National Geographic Society – Palomar Observatory Sky Survey plates by Robert George Harrington and Fritz Zwicky,[7] it was initially catalogued as a globular cluster; however, Zwicky came to believe it was actually a nearby dwarf galaxy in the Local Group.
[5] It has an average luminosity distribution of Mv = −4.48.
[8] Based on proper motion studies, this cluster was first suspected in 2000 to have been captured from the Sagittarius Dwarf Elliptical Galaxy (SagDEG) about 1.7 Ga ago.
[9] It is now generally believed to have originated in that galaxy and is associated with the Sagittarius Stream.