GD-1

In 2006, GD-1 is identified as a moving group of old, metal-poor stars located at 8.5 kpc above the galactic disk and spanning 63 degrees across the sky. ^[1] The stream was formed after a globular cluster was disrupted by tidal forces, possibly from the gravitational field of the Milky Way. The stream is located within the Field of Streams, a region of sky in the galactic northern hemisphere containing many stellar streams, the most prominent of which is the Sagittarius stream.^[2]

The stream's progenitor is believed to be a globular cluster based on the stream's radial velocity, location and the age of the stars within,^[1] but the specific cluster has not been identified.