Arp 7

Arp 7 (PGC 24836) is a spiral galaxy in the constellation Hydra.^[1] Redshift-independent measurements of its distance vary widely, from 5.9 to 83.7 megaparsecs (19.24 to 273.0 million light-years).^[3] Its morphological classification is SB(rs)bc,^[3] meaning it is a barred spiral galaxy with some ring-like structure.

Arp 7
Arp 7 by PanSTARRS
Observation data (J2000 epoch)
Constellation	Hydra[1]
Right ascension	8h 50m 30.0s[2]
Declination	−16° 37′ 00″[2]
Redshift	0.018620±0.000002[3]
Heliocentric radial velocity	5,582±1 km/s[3]
Galactocentric velocity	5,384±8 km/s[4][3]
Distance	103.9 ± 146.4 Mly (31.853 ± 44.901 Mpc)[3]
Apparent magnitude (V)	14.5[3]
Characteristics
Type	SB(rs)bc: HII[3]
Size	40,737 ly (12.49 kpc) (diameter; 25.0 B-mag arcsec−2)[3][a] 28,767 ly × 26,451 ly (8.82 kpc × 8.11 kpc) (diameter; "total" magnitude)[3][a]
Apparent size (V)	1.3′ × 1.0′ [3]
Other designations
PGC 024836,[3] APG 7[2]

Arp 7 was imaged by Halton Arp and included in his Atlas of Peculiar Galaxies under the category of 'split arm' galaxies.^[5] Five other galaxies are also included in this section of the atlas: Arp 8 (NGC 497), Arp 9 (NGC 2523), Arp 10 (UGC 1775), Arp 11 (UGC 717), and Arp 12 (NGC 2608).