Messier 84 | |
---|---|
Observation data ( J2000 epoch) | |
Constellation | Virgo |
Right ascension | 12h 25m 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 84 or M84, also known as NGC 4374, is a giant elliptical or lenticular 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 clusters is 1,775±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 4387 or M86. [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]
Messier 84 | |
---|---|
Observation data ( J2000 epoch) | |
Constellation | Virgo |
Right ascension | 12h 25m 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 84 or M84, also known as NGC 4374, is a giant elliptical or lenticular 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 clusters is 1,775±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 4387 or M86. [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]