Leo II (dwarf galaxy)
Dwarf Spheroidal galaxy in the constellation Leo
From Wikipedia, the free encyclopedia
Leo II (or Leo B) 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.[4] Leo II is thought to have a core radius of 178 ± 13 pc and a tidal radius of 632 ± 32 pc.[5] It was discovered in 1950 by Robert George Harrington and Albert George Wilson, from the Mount Wilson and Palomar Observatories in California.
.jpg)
| Leo II | |
|---|---|
| |
| Observation data (J2000 epoch) | |
| Constellation | Leo |
| Right ascension | 11h 13m 29.2s [1] |
| Declination | +22° 09′ 17″ [1] |
| Redshift | 0.000264 (79 ± 1 km/s) [1] |
| Distance | 690 ± 70 kly (210 ± 20 kpc)[2] [3] |
| Apparent magnitude (V) | 12.6 [1] |
| Characteristics | |
| Type | E0 pec [1] |
| Apparent size (V) | 12.0 x 11.0 arcmin [1] |
| Other designations | |
| PGC 34176, DDO 93 | |
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 (e.g., the Milky Way) consume smaller galaxies to attain their extensive size.[6]
Observation at ESO estimates Leo II's mass to be (2.7 ± 0.5)×107 M☉.[7]
See also
- Dwarf galaxy
- Local Group, a description of the group of galaxies that includes the Milky Way.
