IC 21
| Galaxy IC 21 |
|
|---|---|
|
|
| SDSS recording | |
| AladinLite | |
| Constellation | whale |
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Position equinox : J2000.0 , epoch : J2000.0 |
|
| Right ascension | 00 h 29 m 10.4 s |
| declination | -00 ° 09 ′ 50 ″ |
| Appearance | |
| Morphological type | SBbc |
| Brightness (visual) | 15.2 mag |
| Brightness (B-band) | 16.0 mag |
| Angular expansion | 0.5 ′ × 0.4 ′ |
| Surface brightness | 13.3 mag / arcmin² |
| Physical data | |
| Redshift | 0.060639 +/- 0.000150 |
| Radial velocity | 18179 +/- 45 km / s |
|
Stroke distance v rad / H 0 |
(816 ± 57) · 10 6 Lj (250.3 ± 17.5) Mpc |
| diameter | 120,000 ly |
| history | |
| discovery | Stéphane Javelle |
| Discovery date | November 7, 1891 |
| Catalog names | |
| IC 21 • PGC 1785 • MCG + 00-02-053 • SDSS J002910.42-000949.6 | |
IC 21 is a bar-spiral galaxy of the Hubble type SB (rs) b? in the constellation whale in the southern sky . It is around 816 million light years away from the Milky Way and has a diameter of around 90,000 light years .
Probably the object is gravitationally to his neighbor galaxy PGC 3112047 tied , they almost have the same radial velocity .
IC 21 was discovered on November 7th, 1891 by Stéphane Javelle .