NGC 4772
Galaxy in the constellation Virgo
From Wikipedia, the free encyclopedia
NGC 4772 is a spiral galaxy in the constellation Virgo. The galaxy lies about 90 million light years away from Earth based on redshift-independent methods, which means, given its apparent dimensions, that NGC 4772 is approximately 85,000 light years across. Based on redshift the galaxy lies at a distance of 13.3 Mpc (43.4 Mly).[1] It was discovered by William Herschel on January 24, 1784.[3]
| NGC 4772 | |
|---|---|
NGC 4772 imaged by SDSS | |
| Observation data (J2000 epoch) | |
| Constellation | Virgo |
| Right ascension | 12h 53m 29.1613s[1] |
| Declination | +02° 10′ 06.157″[1] |
| Redshift | 0.003469 ± 0.000017 [1] |
| Heliocentric radial velocity | 1,040 ± 5 km/s[1] |
| Distance | 88.2 ± 30.1 Mly (27.0 ± 9.2 Mpc)[1] |
| Group or cluster | NGC 4753 Group |
| Apparent magnitude (V) | 10.7[2] |
| Characteristics | |
| Type | SA(s)a [1] |
| Size | ~87,000 ly (26.6 kpc) (estimated)[1] |
| Apparent size (V) | 3.4′ × 1.7′ [1] |
| Other designations | |
| UGC 8021, MCG +00-33-018, PGC 43798, CGCG 015-032[1] | |
Characteristics
NGC 4772 has a bright circular galactic bulge. The galaxy has a long and broad low-surface-brightness bar in the bulge.[4][5] The kinematics of the central region indicate the presence of a misaligned bar or disk.[6] However it could also indicate the presence of counter-rotating gas,[7] with the galaxy being at the late stages of a minor merger.[6] The central region of the galaxy is depleted in hydrogen[6] and also has low carbon monoxide emission.[8] The nucleus of the galaxy has been found to be active and based on its spectrum it has been characterised as a type 1.9 LINER.[9]
The galaxy has two faint, narrow arms which wrap around the galaxy and form a ring.[4] An outer ring is visible, but appears segmented on its northern and southern part. A dust lane surrounds the bulge. The dust lane has some filaments which resemble a spiral structure.[6] The dust lane region also features H-alpha and hydrogen line emission. The hydrogen emission is distributed in two rings around the nucleus. The inner ring has a radius of 60 arcseconds and the outer ring a radius of 200 arcseconds. There is a faint blue stellar location at the outer ring, while the inner ring coincides with active star formation regions. The two rings have slightly different position angles.[6] Carbon monoxide emission is asymmetric and is distributed along the inner hydrogen ring.[8] The star formation rate of the galaxy is about 0.03 M☉ per year.[8]
Supernovae
Two supernovae have been observed in NGC 4772:
- SN 1988E was discovered on 20 January 1988 by Yoshiaki Taniguchi at an apparent magnitude of 17.[10] It was initially identified as a type II supernova well past maximum,[11] but further observations found it was depleted in hydrogen and was thus reclassified as a type I supernova about 300 days post maximum light.[12]
- SN 2012cu was discovered on 14 June 2012 by Koichi Itagaki at an apparent magnitude of 16.3. Its spectrum revealed it was a type Ia supernova near maximum light.[13] The supernova was highly reddened due to extinction by dust.[14]
Nearby galaxies
NGC 4772 is a member of the NGC 4753 Group, along with NGC 4629, NGC 4691, NGC 4753, NGC 4771, NGC 4845, and NGC 4904.[15] It is part of a Virgo II Groups, a chain of groups extending from the Virgo Cluster.[16] NGC 4772 lies near the outer regions of the Virgo Cluster and has been considered an outlying member of it. The high-surface brightness galaxy CGCG 015-036 lies 18.5 arcminutes away, while the galaxy pair of NGC 4809 and NGC 4810 lies 35 arcminutes to the northeast and at a similar redshift.[6]
Gallery
NGC 4772 by the Legacy Survey
NGC 4772 by the Hubble Space Telescope
