Messier 99

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Messier 99 Spiral Galaxy Messier 99
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
NGC 4254,[1] UGC 7345,[1] PGC 39578,[1]
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.

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[edit] References

  1. ^ a b c d e f g h i j NASA/IPAC Extragalactic Database. Results for NGC 4254. Retrieved on 2006-11-25.
  2. ^ a b SIMBAD Astronomical Database. Results for NGC 4254. Retrieved on 2006-11-25.