Leo A
Coordinates: 
09h 59m 26.4s, +30° 44′ 47″
09h 59m 26.4s, +30° 44′ 47″| Leo A | |
|---|---|
| Apparent magnitude (V) | 12.9[1] |
| Characteristics | |
| Type | IBm[1] |
| Apparent size (V) | 5.1′ × 3.1′[1] |
| Other designations | |
| Leo III, UGC 5364, DDO 69, PGC 28868[1] | |
Leo A (also known as Leo III) is an
2.6 million light-years from Earth, and was discovered by Fritz Zwicky in 1942.[4] The estimated mass of this galaxy is (8.0 ± 2.7) × 107 solar masses, with at least 80% consisting of dark matter.[5] It is one of the most isolated galaxies in the Local Group and shows no indications of an interaction or merger for several billion years. However, Leo A is nearly unique among irregular galaxies in that more than 90% of its stars formed more recently than 8 billion years ago, suggesting a rather unusual evolutionary history.[6] The presence of RR Lyrae variables shows that the galaxy has an old stellar population that is up to 10 billion years in age.[7]
The neutral hydrogen in this galaxy occupies in a volume similar to its optical extent, and is distributed in a squashed, uneven ring. The galaxy is not rotating and the hydrogen is moving about in random clumps. The proportion of elements with higher
O-class stars.[8]
References
- ^ a b c d e f g "NASA/IPAC Extragalactic Database". Results for Leo A. Retrieved 2006-11-19.
- doi:10.1086/382905.
- S2CID 120973010.
- .
- S2CID 16639879.
- S2CID 14268757.
- S2CID 14883376.
- doi:10.1086/177141.
External links
Media related to Leo A at Wikimedia Commons- Leo A on
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