Hoag's Object
| Hoag's Object | |
|---|---|
Hoag's Object, taken by the Hubble Space Telescope in July 2001 | |
| Observation data (J2000 epoch) | |
| Constellation | Serpens Caput |
| Right ascension | 15h 17m 14.407s |
| Declination | +21° 35′ 07.856″ |
| Redshift | 0.042423±0.000009 |
| Heliocentric radial velocity | 12,718±3 km/s |
| Galactocentric velocity | 12,795±4 km/s |
| Distance | 594.3 ± 41.75 Mly (182.2 ± 12.8 Mpc)h−1 0.6774 (Comoving) 558 Mly (171.1 Mpc)h−1 0.6774 (Light-travel) |
| Apparent magnitude (V) | 15.1 |
| Apparent magnitude (B) | 16.2 |
| magnitude (J) | 14.230±0.046 |
| magnitude (H) | 13.536±0.046 |
| magnitude (K) | 13.230±0.044 |
| Characteristics | |
| Type | (RP)E0 or (RP)SA0/a |
| Size | 148,110 ly × 87,377 ly (45.41 kpc × 26.79 kpc) (diameter; 25.0 B-mag arcsec−2) 100,550 ly × 86,464 ly (30.83 kpc × 26.51 kpc) (diameter; "total" magnitude) |
| Apparent size (V) | 0.342357′ × 0.31757′ |
| Notable features | Ring galaxy |
| Other designations | |
| PRC D-51, PGC 54559 | |
Hoag's Object is an unusual ring galaxy in the constellation of Serpens Caput. It is named after Arthur Hoag, who discovered it in 1950 and identified it as either a planetary nebula or a peculiar galaxy. The galaxy has a D25 isophotal diameter of 45.41 kiloparsecs (148,000 light-years).