NGC 4747
Galaxy in the constellation of Coma Berenices
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NGC 4747 is a barred spiral galaxy located in the constellation Coma Berenices. It is located at a distance of about 35 million light years from Earth, which, given its apparent dimensions, means that NGC 4747 is about 35,000 light years across.[1] It was discovered by William Herschel on April 6, 1785.[2] It is included in the Atlas of Peculiar Galaxies in the interior absorption category.
| NGC 4747 | |
|---|---|
NGC 4747 by legacy surveys | |
| Observation data (J2000 epoch) | |
| Constellation | Coma Berenices |
| Right ascension | 12h 51m 45.9s[1] |
| Declination | +25° 46′ 37″[1] |
| Redshift | 0.003969 ± 0.000003 [1] |
| Heliocentric radial velocity | 1,190 ± 1 km/s[1] |
| Distance | 32 Mly (9.8 Mpc)[1] |
| Apparent magnitude (V) | 12.4 |
| Characteristics | |
| Type | SBcd? pec [1] |
| Apparent size (V) | 3.5′ × 1.2′[1] |
| Notable features | tidal tail |
| Other designations | |
| UGC 8005, Arp 159, CGCG 129-028, MCG +04-30-023, PGC 43586[1] | |
The galaxy is a member of the Coma I Group, which is part of the Local Supercluster.[3] NGC 4747 is interacting with neighboring spiral galaxy NGC 4725, with its spiral arms showing indications of warping. The pair have an angular separation of 24′, which corresponds to a projected linear separation of 370 kly.[4] A close approach between NGC 4747 and the more massive NGC 4725 that took place 320 million years before observed created tidal plumes in NGC 4747.[5]
A short tidal plume extends from NGC 4747 toward NGC 4725, to the south-west, and one more pronounced towards the north-east,[6] with a length of 8 arcminutes. The optical north-east plume has also a hydrogen counterpart, which is offset by 50 degrees from the visual counterpart.[4] Two knots, possibly star clusters, are visible in the northeast plume, that could become tidal dwarf galaxies, as they appear to be massive enough to be self-gravitating.[7][8]
The star formation rate of the galaxy is estimated to be 0.13 solar masses per year.[9]
