| NGC 2997 | |
|---|---|
 NGC 2997 | |
| Observation data (J2000epoch) | |
| Constellation | Antlia |
| Right ascension | 09h 45m 38.75379s[1] |
| Declination | −31° 11′ 27.3570″[1] |
| Heliocentric radial velocity | 1,088±2 km/s[2] |
| Distance | 39.8 megalight-years (12.2 Mpc)[3] |
| Group orcluster | NGC 2997 group |
| Apparent magnitude (V) | 10.1[2] |
| Characteristics | |
| Type | SAB(rs)c[4] or Sc(s)I.3[5] |
| Size | 120,000ly (36.65kpc) (estimated)[2] |
| Apparent size (V) | 8′.9 × 6′.8[2] |
| Other designations | |
| ESO 434-35, AM 0943-305,NGC 2997[6],UGCA 181,MCG -05-23-012,PGC 27978[2] | |
NGC 2997 is a face-onunbarred spiral galaxy about 40[3] millionlight-years away in the faint southernconstellation ofAntlia.[3] It was discovered March 4, 1793 by German-born astronomerWilliam Herschel.J. L. E. Dreyer described it as, "a remarkable object, very faint, very large, very gradually then very suddenly bright middle and 4 arcsec nucleus.[7] This is the brightest galaxy of theNGC 2997 group of galaxies, and was featured on the cover of the first edition ofGalactic Dynamics byJames Binney andScott Tremaine.[8]
This is agrand-design galaxy with a symmetrical, two-armed form.[5] Themorphological classification of NGC 2997 is SAB(rs)c,[4] indicating a weakly-barred spiral galaxy (SAB) with an incomplete ring around the bar (rs) and loosely-woundspiral arms (c). It is inclined at an angle of 40° to theline of sight from the Earth, with themajor axis aligned along aposition angle of 110°.[9] The arms host a series of dusty knots that arestar-forming regions being generated through gas compression fromdensity waves.[5] At the core, the arms converge to form a circumnuclear ring with symmetrically-placed hot spots containingsuper star clusters.[4]
A pair ofsupernova events have been detected in the proximity of this galaxy.CCD images taken October 24, 2003 revealed supernova SN 2003jg, positioned11″ east and6″ north of the galactic nucleus.[10] This was determined to be aType Ib/c supernova.[11]Supernova SN 2008eh was reported on July 21, 2008, reaching magnitude 15.0. It was positioned123″ east and34″ north of the galactic core.[12]
Media related toNGC 2997 at Wikimedia Commons
