| NGC 4747 | |
|---|---|
 NGC 4747 bylegacy surveys | |
| Observation data (J2000epoch) | |
| 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 ± 1km/s[1] |
| Distance | 32Mly (9.8Mpc)[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] | |
NGC 4747 is abarred spiral galaxy located in the constellationComa Berenices. It is located at a distance of about 35 millionlight years from Earth, which, given its apparent dimensions, means that NGC 4747 is about 35,000 light years across.[1] It was discovered byWilliam Herschel on April 6, 1785.[2] It is included in theAtlas of Peculiar Galaxies in the interior absorption category.
The galaxy is a member of theComa I Group, which is part of theLocal Supercluster.[3] NGC 4747 is interacting with neighboring spiral galaxyNGC 4725, with its spiral arms showing indications of warping. The pair have anangular separation of24′, 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 ahydrogen counterpart, which is offset by 50 degrees from the visual counterpart.[4] Two knots, possiblystar clusters, are visible in the northeast plume, that could become tidaldwarf galaxies, as they appear to be massive enough to be self-gravitating.[7][8]
Thestar formation rate of the galaxy is estimated to be 0.13 solar masses per year.[9]
