| NGC 4442 | |
|---|---|
 DESI Legacy DR10 image of NGC 4442 | |
| Observation data (J2000epoch) | |
| Constellation | Virgo |
| Right ascension | 12h 28m 03.88s |
| Declination | +09° 48' 13.43" |
| Redshift | 0.00117 |
| Heliocentric radial velocity | 351 |
| Distance | 48.01Mly (14.72Mpc) |
| Group orcluster | Virgo Cluster |
| Apparent magnitude (V) | 10.6 |
| Characteristics | |
| Type | SB0 |
| Mass | 162.2 billion M☉ |
| Size | 83,100ly (25,490pc) |
| Other designations | |
| UGC 7583, LEDA 40950, Z 70-100, VCC 1062 | |
NGC 4442 also known asUGC 7583, is abarred lenticular galaxy,luminous infrared galaxy andactive galaxy in the constellation ofVirgo.[1][2] The galaxy is 48 millionlight years (or 14,720,000parsecs) away at a spectroscopic redshift z = 0.00117.[2][3] The galaxy has a visual magnitude of 10.6[3], which is visible using a telescope with an aperture of 6 inches or more, and it can be observed in both hemispheres during certain times of the year.[4] The galaxy is located in theVirgo Cluster, along with other notable galaxies such asMessier 87 and theEyes Galaxies.[1] The galaxy was discovered on April 15, 1784 by German-British astronomer,William Herschel.[5]
NGC 4442 is medium-sizedbarred lenticular galaxy located in theVirgo Cluster, and it was listed as the 1,062nd object in the Virgo Cluster Catalog (VCC).[1][2] The galaxy has an estimated width of 83,000 light years (or 25,490 parsecs) across, or about 3/4 the size of theMilky Way.[2] This size is based on an 2MASS K-band total angular diameter of 5.95arcmin (or 357 arcsecs) and a mean redshift-independent distance of 48 million light years (or 14,720,000 parsecs).[2]
NGC 4442 has a stellar mass of 162 billionM☉, or 10^11.21.[6] The galaxy is roughly 3/4th the stellar mass of theMilky Way.[6] The galaxy has a large stellar population ofred-giant branch stars (also known as RGB stars), with an average age of 3.92 billion years old, and an mean mass of 1.09M☉.[7] Theneutral atomic hydrogen in the galaxy has an mass of 54.9 millionM☉, and this gas is usually found in the outer regions of the galaxy such as thegalactic halo.[6]
NGC 4442 has a K-band luminosity of 550 billionL☉, or 10^11.74 and therefore it is classified as aluminous infrared galaxy (also referred as LIRGs).[6] The galaxy is one of the closest luminous infrared galaxies known[2], with a similar distance to other nearby luminous infrared galaxies such asMessier 77.
NGC 4442 has a star-formation rate of 10.7M☉ per year, extremely high for gas-poor lenticular galaxies.[8] Despite its high-star formation rate it is not classified as astarburst galaxy, and the galaxy's star-formation rate is comparable to other lenticular galaxies such asMessier 85.[9] The total mass of theionized atomic hydrogen in the galaxy, which mostly includes the star-forming regions is 109.6 millionM☉, or 10^8.04.[6]
The galactic center of NGC 4442 shows a clearactive galactic nucleus (also called AGNs), which is a region at the center of a galaxy that is extremely luminous and bright.[1][9] The active galactic nucleus is powered by a massivesupermassive black hole (also known as SMBHs) with a mass of 5.25 billionM☉[10] or roughly 1,200 times more massive thanSagittarius A*, which is the central black hole of theMilky Way.
NGC 4442 has a population of 219globular clusters, however some of them are potentially not globular clusters and are candidates.[11][12] The globular clusters have angular radii between 0.0103 and 0.1042 arcsecs, corresponding to ahalf-light radius ranging from 2.41 to 24.3 light years (or 0.74 to 7.44 parsecs).[11]
Onesupernova has been identified in NGC 4442:SN 2021qvv, which had a peak magnitude of 13.8 in July 2021, and it was classified as aType Ia supernova (abbreviated as SNIa).[13] SN 2021qvv was discovered on June 24, 2021, by theLas Cumbres Observatory.[13] The supernova had a maximumabsolute luminosity of -16.42, equivalent to 316 millionL☉ and was considered a underluminous supernova similar to other supernovae such asSN 2006mr.[13] The supernova was formed by the collision of twowhite dwarfs with predicted masses of 0.85M☉ and 1.1M☉, creating asuper-Chandrasekhar white dwarf which collapsed and exploded.[13]
