Arp 81
| Galaxy pair Arp 81 / VV 247 (NGC 6621, NGC 6622) |
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| Photo of the Hubble Space Telescope ; left NGC 6621 (A), right NGC 6622 (B) | |
| AladinLite | |
| Constellation | Dragon |
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Position equinox : J2000.0 , epoch : J2000.0 |
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| Right ascension | 18 h 12 m 57.5 s |
| declination | + 68 ° 21 ′ 30 ″ |
| Appearance | |
| Morphological type | A: Sb: pec; HII; LIRG B: Sa |
| Brightness (visual) | A: 13.2 mag B: 15.0 mag |
| Brightness (B-band) | A: 14.0 mag B: 15.8 mag |
| Angular expansion | A: 2 ′, 1 × 0 ′, 8 B: 0 ′, 9 × 0 ′, 4 |
| Position angle | A: 145 ° B: 145 ° |
| Surface brightness | A: 13.6 mag / arcmin 2 B: 13.7 mag / arcmin² |
| Physical data | |
| Affiliation | Coma pile |
| Redshift | 0.020652 ± 0.000007 B: 0.021568 ± 0.000100 |
| Radial velocity | (6191 ± 2) km / s B: (6466 ± 30) km / s |
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Stroke distance v rad / H 0 |
(286 ± 20) x 10 6 ly (87.6 ± 6.1) Mpc |
| history | |
| discovery | Edward Swift |
| Discovery date | June 2, 1885 |
| Catalog names | |
| NGC 6621 (A) / 6622 (B) • UGC 11175 • PGC 61582 (A) / 61579 (B) • CGCG 322-036 • MCG + 11-22-30 (A) / + 11-22-31 (B) • IRAS 18131 + 6820 • Arp 81 • VV 247 • KPG 534 • Kaz 194 • VII Zw 778 • | |
Arp 81 , also known as VV 247 , is an interacting pair of galaxies in the Draco constellation . It is about 290 million light years from the Milky Way . Halton Arp organized his catalog of unusual galaxies into groups according to purely morphological criteria. This galaxy belongs to the class spiral galaxies with a large companion of high surface brightness on one arm .
In NGC , the galaxies were given the names NGC 6621 and NGC 6622 . The galaxies were discovered on June 2, 1885.
Web links
Commons : Arp 81 - collection of images, videos and audio files
- Hubble Space Telescope
- Arp 81: 100 Million Years Later - Astronomy Picture of the Day of December 11, 2003.
- ARP ATLAS OF PECULIAR GALAXIES
- Seligman Arp
literature
- Jeff Kanipe and Dennis Webb: The Arp Atlas of Peculiar Galaxies - A Chronicle and Observer's Guide , Richmond 2006, ISBN 978-0-943396-76-7