| NGC 278 | |
|---|---|
 NGC 278 byHST | |
| Observation data (J2000epoch) | |
| Constellation | Cassiopeia |
| Right ascension | 00h 52m 04.3s[1] |
| Declination | +47° 33′ 02″[1] |
| Redshift | 0.002090[2] |
| Heliocentric radial velocity | 627±1 km/s[1] |
| Distance | 39 Mly (12.1 Mpc)[3] |
| Group orcluster | Virgo Supercluster[4] |
| Apparent magnitude (V) | 11.5[1] |
| Absolute magnitude (B) | −19.6[2] |
| Characteristics | |
| Type | SAB(rs)b[3] |
| Apparent size (V) | 2′.1 × 2′.0[2] |
| Other designations | |
| UGC 528,[1]PGC 3051[1] | |
NGC 278 is an isolated[3]spiral galaxy in the northerncircumpolar constellation ofCassiopeia, near the southern constellation boundary withAndromeda. It lies at a distance of approximately 39megalight-years from theMilky Way, giving it a physical scale of 190 ly (58 pc) perarcsecond.[3] The galaxy was discovered on December 11, 1786 by German-born astronomerWilliam Herschel.J. L. E. Dreyer described it as, "considerably bright, pretty large, round, 2 stars of 10th magnitude near".[5]
Themorphological classification of this galaxy is SAB(rs)b,[3] which indicates a weakbar structure around the nucleus (SAB), an incomplete ring around the bar (rs), and moderately-tightly woundspiral arms (b). It is a relatively small, compact spiral[3] with a diameter of 23 kly (7 kpc),[2] multipleflocculent arms and a bright, dusty nucleus that does not appear to beactive.[3] However, theneutral hydrogen in the galaxy is spread over a diameter five times larger than its visible size.[2]
Although it appears nearly face-on, thegalactic plane isinclined by an angle of 28° to theline of sight from theEarth, with themajor axis being oriented along aposition angle of 116°.[3] The outer part of the disk appears to be warped, so that the major axis is not quite perpendicular to the minor axis,[6] and the morphology is somewhat disrupted.[2] The inner disk contains multiple intensestar-forming regions.[3] This is taking place in an inner ring with a radius of 6.5 kly (2 kpc) that may have been triggered by amerger with a smaller companion.[4] It has anH II nucleus.[7]
Media related toNGC 278 at Wikimedia Commons
