NGC 3991
| Galaxy NGC 3991 |
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|---|---|
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| SDSS image of NGC 3991 | |
| AladinLite | |
| Constellation | Big Bear |
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Position equinox : J2000.0 , epoch : J2000.0 |
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| Right ascension | 11 h 57 m 31.1 s |
| declination | + 32 ° 20 ′ 16 ″ |
| Appearance | |
| Morphological type | In the pec |
| Brightness (visual) | 13.0 likes |
| Brightness (B-band) | 13.6 mag |
| Angular expansion | 1.3 ′ × 0.3 ′ |
| Position angle | 33 ° |
| Surface brightness | 11.8 mag / arcmin² |
| Physical data | |
| Affiliation | LGG 259 |
| Redshift | 0.010647 +/- 0.000017 |
| Radial velocity | 3192 +/- 5 km / s |
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Stroke distance v rad / H 0 |
(143 ± 10) · 10 6 ly (43.7 ± 3.1) Mpc |
| history | |
| discovery | Heinrich d'Arrest |
| Discovery date | February 5, 1864 |
| Catalog names | |
| NGC 3991 • UGC 6933 • PGC 37613 • CGCG 186-073 • MCG + 06-26-060 • IRAS 11549 + 3237 • KUG 1154 + 326 • 2MASX J11573046 + 3220030 • Arp part of 313 • VV 523 • HARO 5 | |
NGC 3991 is an irregular galaxy of Hubble type in Big Bear in the constellation of the northern sky . It is an estimated 143 million light years away from the Milky Way and has a diameter of about 55,000 ly. Together with NGC 3994 and NGC 3995 , it forms the galaxy trio Arp 313 . Halton Arp organized his catalog of unusual galaxies into groups according to purely morphological criteria. This galaxy triplet belongs to the class of galaxy groups .
The object was discovered on February 5, 1864 by the astronomer Heinrich Louis d'Arrest .
Web links
Commons : NGC 3991 - collection of images, videos, and audio files
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