| NGC 7625 | |
|---|---|
 Sloan Digital Sky Survey image of NGC 7625 | |
| Observation data (J2000 epoch) | |
| Constellation | Pegasus |
| Right ascension | 23h 20m 30.132s [1] |
| Declination | +17° 13′ 32.16″ [1] |
| Heliocentric radial velocity | 1,630±3 km/s [2] |
| Distance | 78.3 ± 7.5 Mly (24.0 ± 2.3 Mpc) [3] |
| Apparent magnitude (V) | 12.9 [4] |
| Apparent magnitude (B) | 12.94 [5] |
| Characteristics | |
| Type | Sa/S pec [6] |
| Mass/Light ratio | 2.5 [4] M☉/L☉ |
| Apparent size (V) | 1.6′ × 1.4′ [5] |
| Other designations | |
| NGC 7625, Arp 212, UGC 12529, LEDA 71133, MCG +03-59-038, PGC 71133 [7] | |
NGC 7625, or Arp 212, is a peculiar galaxy in the constellation of Pegasus. It was discovered on October 15, 1784, by William Herschel. [8] In his New General Catalogue (1888), J. L. E. Dreyer described it as pretty bright, considerably small, round, with a suddenly much brighter middle. [9] It is located at an estimated distance of 78 million light-years (24.0 megaparsecs ) from the Milky Way galaxy. [3]
Halton Arp included NGC 7625 as object 212 in his Atlas of Peculiar Galaxies , indicating it displayed unexplained physical processes. [10] In the Third Reference Catalogue of Bright Galaxies, NGC 7625 was assigned a morphological classification of SA(rs)a pec, which indicates a peculiar spiral galaxy (SA) with a transitional ring structure (rs) and tightly wound spiral arms (a). [11] In 1981 it was designated a blue compact dwarf by T. X. Thaun and G. E. Martin on the basis of strong emission lines from ionized gas. [12] A prominent visible feature is an open ring of dust lanes with an angular radius of about 15″–20″. [13]
NGC 7625 displays indications of a recent interaction with another galaxy. Velocity measurements suggest the inner part of the galaxy is rotating in a different plane than the outer parts. The angle between these two planes increases with distance from the galactic center, reaching 50° at a radius of 6 kpc. Hence this may be a polar-ring galaxy, with the added gas accreted from the dwarf satellite galaxy UGC 12549. [13] There is a large amount of gas and dust undergoing significant star formation, with emission of H-alpha concentrated at the core and in separate knots along exterior curved structures. [6]
On October 28, 2023 type Ia supernova SN 2023vyl was discovered in this galaxy by ATLAS. [14] [15]
