12h25m03.7s, +12° 53′13″| Messier84 | |
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Galaxy Messier 84 in Virgo, imaged by the Hubble Space Telescope
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| Observation data (J2000 epoch) | |
| Constellation | Virgo |
| Right ascension | 12h25m 03.74333s[1] |
| Declination | +12° 53′ 13.1393″[1] |
| Redshift | 1,060±6 km/s[2] |
| Heliocentric radial velocity | 999[3] km/s |
| Distance | 54.9 Mly (16.83 Mpc)[3] |
| Apparent magnitude (V) | 9.1[4] |
| Absolute magnitude (V) | −22.41±0.10[5] |
| Characteristics | |
| Type | E1[5] |
| Apparent size (V) | 6.5′ × 5.6′[2] |
| Half-light radius (apparent) | 72.5″±6″[5] |
| Other designations | |
| M84, NGC 4374, PGC 40455, UGC 7494, VCC 763[6] | |
Messier 84orM84, also known as NGC 4374, is a giant ellipticalorlenticular galaxy in the constellation Virgo. Charles Messier discovered the object in 1781[a] in a systematic search for "nebulous objects" in the night sky.[7] It is the 84th object in the Messier Catalogue and in the heavily populated core of the Virgo Cluster of galaxies, part of the local supercluster.[8]
This galaxy has morphological classification E1, denoting it has flattening of about 10%. The extinction-corrected total luminosity in the visual band is about 7.64×1010 L☉. The central mass-to-light ratio is 6.5, which, to a limit, steadily increases away from the core. The visible galaxy is surrounded by a massive dark matter halo.[5]
Radio observations and Hubble Space Telescope images of M84 have revealed two jets of matter shooting out from its center as well as a disk of rapidly rotating gas and stars indicating the presence of a 1.5 ×109 M☉[9] supermassive black hole. It also has a few young stars and star clusters, indicating star formation at a very low rate.[10] The number of globular clustersis1,775±150, which is much lower than expected for an elliptical galaxy.[11]
Viewed from Earth its half-light radius, relative angular size of its 50% peak of lit zone of the sky, is 72.5″, thus just over an arcminute.
Two supernovae have been observed in M84: SN 1957B[12] and SN 1991bg.[13] Seen between these dates, it may have bore a third, SN 1980I – which may have been in either neighboring galaxy NGC 4387orM86.[14] This high rate of supernovae is rare for elliptical galaxies, which may indicate there is a population of stars of intermediate age in M84.[11]
Stars
Outer space|
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| List |
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| See also |
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New General Catalogue 4000 to 4499
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