| 3C 20 | |
|---|---|
 | |
| Observation data (J2000 epoch) | |
| Constellation | Cassiopeia |
| Right ascension | 00h 43m 09.18s [1] [2] |
| Declination | +52° 03′ 36.15″ [1] [2] |
| Redshift | 0.174±0.001 [3] |
| Heliocentric radial velocity | 52,164±300 km/s [3] |
| Galactocentric velocity | 52,352±300 km/s [3] |
| Distance | 2,501 ± 175.5 Mly (766.7 ± 53.8 Mpc)h−1 0.6774 (Comoving) [3] 2.213 Gly (678.5 Mpc)h−1 0.6774 ( Light-travel ) [3] |
| Apparent magnitude (V) | 19.0 [3] |
| Apparent magnitude (B) | 19.0 [2] |
| magnitude (J) | 16.368±0.112 [4] |
| magnitude (H) | 15.582±0.126 [4] |
| magnitude (K) | 14.756±0.115 [4] |
| Characteristics | |
| Type | NLRG [3] |
| Apparent size (V) | 76.8″ × 76.8″ ² [5] (radiogalaxy) |
| Other designations | |
| DA 22, 3C 20, LEDA 2817481 | |
3C 20 is a radio galaxy [6] located in the constellation Cassiopeia. It features a prominent double hotspot in its eastern lobe. An unusually low fraction of the flux lies within the radio core, which is suggested to be caused by a combination of factors, including jet orientation, synchrotron self-absorption and aging, as well as interactions with surrounding gas and dust. [7]
