Messier 99
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Galaxy | List of galaxies |
---|---|
Observation data (Epoch J2000) |
|
Constellation | Coma Berenices |
Right ascension | 12h 18m 49.6s[1] |
Declination | +14° 24′ 59″[1] |
Redshift | 2407 ± 3 km/s[1] |
Distance | 60 Mly[1] |
Type | SA(s)c[1] |
Apparent dimensions (V) | 5′.4 × 4′.7[1] |
Apparent magnitude (V) | 10.4[1] |
Notable features | One of largest red shifts in the Virgo cluster |
Other designations | |
Coma Pinwheel Galaxy,[2] Virgo Cluster Pinwheel[2] |
Messier 99 (also known as NGC 4254 or M99 for short, nicknamed Coma Pinwheel Galaxy) is an unbarred spiral galaxy approximately 60 million light-years away in the constellation Coma Berenices. It was discovered by Pierre Méchain on the March 17, 1781.
The galaxy has a normal looking arm and an extended arm that is less tightly wound. A bridge of neutral hydrogen gas links NGC 4254 with VIRGOHI21. The gravity from the dark galaxy VIRGOHI21 appears to have distorted M99 and drawn out the gas bridge, as the two galaxy-sized objects have a close encounter, before they go their separate ways. It is expected that the drawn out arm will relax to match the normal arm once the encounter is over. Three supernovae have been observed in this galaxy.
[edit] See also
[edit] External links
- SEDS: Spiral Galaxy M99
- UniverseToday: Dark Matter Galaxy?
- PPARC: New evidence for a Dark Matter Galaxy
- SIMBAD: M 99 -- HII Galaxy
- WIKISKY.ORG: SDSS image, M99