NGC 642
| Galaxy NGC 642 |
|
|---|---|
![NGC 642 & NGC 639 [1]](https://de.wikipedia.org/wiki/Datei:NGC_0642_DSS.jpg)
|
|
| NGC 642 & NGC 639 | |
| AladinLite | |
| Constellation | sculptor |
|
Position equinox : J2000.0 , epoch : J2000.0 |
|
| Right ascension | 01 h 39 m 6.33 s |
| declination | -29 ° 54 ′ 53.6 ″ |
| Appearance | |
| Morphological type | SB (s) c |
| Brightness (visual) | 12.3 mag |
| Brightness (B-band) | 13.0 likes |
| Angular expansion | 1.76 ′ × 0.91 ′ |
| Position angle | 31 ° |
| Surface brightness | 13.0 mag / arcmin² |
| Physical data | |
| Redshift | 0.019624 ± 0.000023 |
| Radial velocity | 5883 ± 7 km / s |
|
Stroke distance v rad / H 0 |
(261 ± 18) x 10 6 ly (80.0 ± 5.6) Mpc |
| history | |
| discovery | John Herschel |
| Discovery date | September 27, 1834 |
| Catalog names | |
| NGC 642 • PGC 6112 • ESO 413-001 • MCG -05-05-003 • IRAS 01367-3010 • 2MASX J01390634-2954534 • SGC 013649-3010.1 • VV 419 • GC 381 • h 2431 • HIPASS J0139-29 • LDCE 103 NED001 | |
NGC 642 is a bar-spiral galaxy of the Hubble type Sa in the constellation Sculptor in the southern sky . It is estimated to be 261 million light years from the Milky Way and about 155,000 light years in diameter. Presumably it forms a gravitationally bound galaxy pair together with NGC 639 .
The object was discovered on September 27, 1834 by the British astronomer John Herschel .
Web links
- SIMBAD Astronomical Database
- Auke Slotegraaf : NGC 642. Deep Sky Observer's Companion, accessed September 4, 2015 .