NGC 383

NGC 383 is a double radio galaxy^[3] with a quasar-like appearance located in the constellation Pisces. It was discovered by German-British astronomer William Herschel on 12 September 1784.^[4] It is listed as Arp 331 in Halton Arp's Atlas of Peculiar Galaxies.^[5]

NGC 383
Hubble Legacy Archive image of NGC 383
Observation data (J2000 epoch)
Constellation	Pisces
Right ascension	01h 07m 24.968s[1]
Declination	+32° 24′ 45.103″[1]
Redshift	0.017005[1]
Distance	209,000,000 ly 64 Mpc[2]
Apparent magnitude (V)	13.4[1]
Characteristics
Type	S0[1]
Size	~149,700 ly (45.91 kpc) (estimated)[1]
Apparent size (V)	2.34′ × 1.95′[1]
Other designations
3C 31, 4C 32.05, QSO B0104+321, UGC 689, MCG +05-03-053, PGC 3982, CGCG 501-087, VV 193a[1]

Recent discoveries by the National Radio Astronomy Observatory in 2006 reveal that NGC 383 is being bisected by high energy relativistic jets traveling at relatively high fractions of the speed of light. The relativistic electrons in the jets are detected as synchrotron radiation in the x-ray and radio wavelengths. The focus of this intense energy is the galactic center of NGC 383. The relativistic electron jets detected as synchrotron radiation extend for several thousand parsecs and then appear to dissipate at the ends in the form of streamers or filaments.

There are four other nearby galaxies NGC 379, NGC 380, NGC 385, and NGC 384 which are suspected of being closely associated with NGC 383, as well as several other galaxies at relatively close distance.

Two supernovae have been observed in NGC 383:

• SN 2015ar (type Ia, mag. 18.8) was discovered by E. Conseil and G. Arlic on 11 November 2015.^[6][7]
• SN 2017hle (type Ia, mag. 18) was discovered by Xingming Observatory Sky Survey (XOSS) on 18 October 2017.^[8]

Two jets coming from 3C 31.

See also

• Relativistic beaming
• Relativistic jets