Leo 1, at right, is a dwarf spheroidal elliptical dE3 galaxy that is a satellite of our own Milky Way Galaxy.

Regulus, at left, is the brilliant first magnitude alpha star of the constellation of Leo.

Located 20 arcminutes north of Regulus, Leo 1 lies at a distance of 900,000 light-years away, which makes it one of the farthest satellite galaxies of the Milky Way. It has an apparent diameter of 10.7 x 8.3 arcminutes on the sky and an apparent visual magnitude of 10.2.

Leo 1, also known as the Regulus Dwarf, was discovered by A. G. Wilson in 1950 on Palomar Sky Survey plates. Along with the Milky Way and its satellite galaxies, it is a member of the local group of galaxies and the Virgo supercluster.

Regulus, Alpha Leonis, is located 79 light-years from Earth. It has a mass of 3.5 times the Sun's mass and is a hot young blue star that shines 360 times brighter than the Sun. Regulus is a multiple star system comprised of four stars, one of which is probably a white dwarf orbiting closely around the primary. The other two stars in the system are located 3 arcminutes away to the northwest. They can be seen in the image as the bright star at the 5 o'clock position nearest to Regulus. They shine at 8th and 13th magnitude.

North is to the right in the above image.

Leo 1 Catalogs: Leo 1, UGC 5470 Common Name: Regulus Dwarf Object Type: Galaxy Magnitude: 10.9b Size: 10.7' x 8.3' Constellation: Leo Image Field Centered At: RA: 10h 08m 27s Dec: +12° 08' 30"