| IC 2531 | |
|---|---|
 The edge-on spiral galaxy IC 2531. | |
| Observation data (J2000epoch) | |
| Constellation | Antlia |
| Right ascension | 09h 59m 55.50s |
| Declination | −29° 37′ 03.2″ |
| Redshift | 0.008246 |
| Heliocentric radial velocity | 2,472km/s |
| Distance | 133Mly (40.77Mpc) |
| Apparent magnitude (V) | 0.27 |
| Apparent magnitude (B) | 0.35 |
| Surface brightness | 13.54 |
| Characteristics | |
| Type | Sb, HII |
| Size | ∼283,000ly (estimated) |
| Apparent size (V) | 7.50' x 0.90' |
| Other designations | |
| PGC 28909,ESO 435-G025,MCG -05-24-015, AM 0957-292, "little N 891" | |
IC 2531 is an edge-onspiral galaxy located in the constellation ofAntlia. It is located 130 millionlight years fromEarth.[1] It was discovered in February 1898, by the AmericanastronomerLewis Swift.[2] The galaxy has been called by its nickname "little N 891" because of its resemblance to another edge-on spiral,NGC 891. However IC 2531 is twice as large.[3]
IC 2531 contains a broadHI line. In addition, it has aluminosity class of III and regions ofionizedhydrogen.[1]
IC 2531 is classified a late-type galaxy with a projected megaparsec of 36.8.[4] It has an Sbmorphological classification.[5] It is seen edge-on and contains adust lane found separating its main body into two equal components.[4] It has a presence of filamentary features reaching itsgalactic halo[6] and high circularvelocity of vmax = 260.5 km−1.[5] IC 2531 also contains a lowfar-infrared flux expecting a relatively lowcontamination of disk light by its youngstar population.[7]
What is striking about IC 2531, is the fact that itsgalactic budge has a peculiar box/peanut-shaped structure.[5][4] Through analyzations of itsatomic hydrogen (HI) content as part of theHerschel observations,[8] a total mass of 1.37 x 1010 MΘ was calculated. The galaxy is also shown to have both its HI andstellar disc extending towards the northeast side. It is found having outer regions slightly wrapped along itsline of sight and theplane of the sky with bothinclination andposition angles straying 4 degrees.[4] Furthermore, IC 2531 shows a protrudingspiral arm in its disk.[8][4]
IC 2531 is a member of the NGC 3054 group. There are nine members in the group besides IC 2531 andNGC 3054 includingNGC 3051,NGC 3078,NGC 3084,NGC 3089,IC 2537 and two other galaxies from theEuropean Southern Observatory Catalog namely ESO 499-26 and ESO 499–325. IC 2531 is the largest member.[9]
