Groombridge 1618 is a star in the northern constellation Ursa Major. With an apparent visual magnitude of +6.6, it lies at or below the threshold of stars visible to the naked eye for an average observer. This is a main sequence star of spectral type K7.5 Ve, having just 67% of the Sun's mass.
Right ascension 10h 11m 22.1400"
Declination +49° 27′ 15.2492"
Distance (Earth) 15.88 ly
Contains Castrovel, the home world of the Lashunta and the Formians.