NGC 3109
| Galaxy NGC 3109 |
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|---|---|
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| GALEX image of NGC 3109 | |
| AladinLite | |
| Constellation | Water snake |
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Position equinox : J2000.0 , epoch : J2000.0 |
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| Right ascension | 10 h 03 m 06.9 s |
| declination | -26 ° 09 ′ 34 ″ |
| Appearance | |
| Morphological type | SB (s) w |
| Brightness (visual) | 9.8 likes |
| Brightness (B-band) | 10.4 mag |
| Angular expansion | 19.1 ′ × 3.7 ′ |
| Position angle | 93 ° |
| Surface brightness | 14.3 mag / arcmin² |
| Physical data | |
| Affiliation | Local group , NGC-3109 subgroup |
| Redshift | (1344 ± 3) · 10 −6 |
| Radial velocity | 403 ± 1 km / s |
| distance | <5 million ly |
| Absolute brightness | −15.3 mag |
| diameter | 21,000 ly |
| history | |
| discovery | John Herschel |
| Discovery date | March 24, 1835 |
| Catalog names | |
| NGC 3109 • UGCA 194 • PGC 29128 • ESO 499-G036 • MCG -04-24-13 • 2MASX J10030687-2609344 • SGC 100049-2555.0 • GC 2003 • h 3221 • AM 1000-255 • DDO 236 | |
NGC 3109 is an irregular dwarf galaxy or a Hubble-type spiral galaxy SB (s) m? in the constellation Water Snake south of the ecliptic . It is around 4.5 million light years away from the Milky Way , on the edge of the Local Group and has a diameter of around 25,000 light years .
NGC 3109 is the dominant galaxy of a small group of galaxies, the NGC 3109 subgroup named after it , to which Sextans A , Sextans B , the Antlia dwarf galaxy and possibly Leo A belong, although their affiliation with the latter is not certain. The matter in the disk of NGC 3109 has the same radial velocity as that in the Antlia dwarf galaxy, with which it apparently still interacts as a result of a collision about 1 billion years ago. NGC 3109 has mostly old Population II stars that contain very few metals. It is probably the largest member of the local galaxy group with the poorest metal content. Also, no evidence of a central compression in the galaxy center has been found so far, which almost excludes the existence of a massive black hole there.
It was discovered on March 24, 1835 by John Herschel during his stay in South Africa.