NGC 6845
| Galaxy NGC 6845 |
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| GALEX image of the galaxy group: NGC 6845A in the center, NGC 6845B above on the left; the components NGC 6845C and NGC 6845D are in this image section, but cannot be clearly seen on this image. | |
| AladinLite | |
| Constellation | telescope |
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Position equinox : J2000.0 , epoch : J2000.0 |
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| Right ascension | 20 h 00 m 58.3 s |
| declination | -47 ° 04 ′ 12 ″ |
| Appearance | |
| Morphological type | SBb SBb S0 S0-a |
| Brightness (visual) | 13.0 mag 14.1 mag 14.4 mag 15.4 mag |
| Brightness (B-band) | 13.8 mag 14.9 mag 15.4 mag 16.3 mag |
| Angular expansion | 2.3 / 1.0 1.1 / 0.6 0.8 / 0.4 0.7 / 0.2 |
| Position angle | 72 ° 6 ° 138 ° 156 ° |
| Surface brightness | 13.8 mag / arcmin² 13.5 mag / arcmin² 13.0 mag / arcmin² 13.2 mag / arcmin² |
| Physical data | |
| Redshift | 0.021211 +/- 0.000140 |
| Radial velocity | 6359 +/- 42 km / s |
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Stroke distance v rad / H 0 |
(283 ± 20) x 10 6 ly (86.8 ± 6.1) Mpc |
| history | |
| discovery | John Herschel |
| Discovery date | July 7, 1834 |
| Catalog names | |
| NGC 6845 • PGC 63978/79/85/86 • ESO 284-008 • IRAS 19573-4712 • Klemola 30, AM 1957-471 | |
NGC 6845 (also known as Klemola 30 ) is an interacting system of four galaxies in the constellation Telescopium . The group has certain similarities with Stephen's quintet . Their distance can be estimated at around 283 million light years from the Milky Way.
The components of the galaxy quartet are the two spiral galaxies NGC 6845A and NGC 6845B and the two lens-shaped galaxies NGC 6845C and NGC 6845D . The four galaxies occupy an area of about 4 '× 2' in the sky. The largest galaxy in this compact group of galaxies is NGC 6845A , a bar-spiral galaxy almost in an edge-on position. SN 2008da was observed in NGC 6845A. The group's companion was identified as the dwarf galaxy ATCA J2001−4659 , which is about 4.4 'away and to the northeast of NGC 6845B.
NGC 6845 was discovered by John Herschel on July 7, 1834 .
literature
- Scott Gordon, Bärbel Koribalski , Keith Jones: Australia Telescope Compact Array HI observations of the NGC 6845 galaxy group . In: Monthly Notice of the Royal Astronomical Society , 342 (3), 2003, pp. 939 ff.
