Leo II (dwarf galaxy)
Leo II is a dwarf spheroidal galaxy about 690,000 light-years away in the constellation Leo. It is one of 24 known satellite galaxies of the Milky Way.
Leo II is thought to have a core radius of 178 ± 13 pc and a tidal radius of 632 ± 32 pc.
It was discovered in 1950 by Robert George Harrington and Albert George Wilson, from the Mount Wilson and Palomar Observatories in California.In 2007 a team of 15 scientists observed Leo II through the 8.2 meter Subaru optical-infrared telescope in Mauna Kea, Hawaii. Over 2 nights, 90 minutes of exposures were taken and 82,252 stars were detected down to a visible magnitude of 26. They found that Leo II consists largely of metal-poor older stars, a sign that it has survived the galactic cannibalism under which massive galaxies consume smaller galaxies to attain their extensive size.
Observation at ESO estimates Leo II's mass to be ×107 M⊙.
