53 Arietis

53 Arietis (abbreviated 53 Ari) is a variable star in the northern constellation of Aries. 53 Arietis is the Flamsteed designation; it also bears the variable star designation UW Arietis. It is a B-type main sequence star with a stellar classification of B1.5 V^[3] and mean apparent magnitude of 6.10,^[2] which is near the lower limit for naked eye visibility. Based upon an annual parallax shift of 3.2 mas, the estimated distance to this star is roughly 1,020 light-years (314 parsecs).

53 Arietis

Observation data Epoch J2000      Equinox J2000
Constellation	Aries
Right ascension	03h 07m 25.67315s[1]
Declination	+17° 52′ 47.9696″[1]
Apparent magnitude (V)	6.10[2]
Characteristics
Spectral type	B1.5 V[3]
U−B color index	[4] 0.80[2]
B−V color index	−0.12[2]
Variable type	β Cep[4]
Astrometry
Radial velocity (Rv)	+21.2[5] km/s
Proper motion (μ)	RA: −23.733[1] mas/yr Dec.: +8.080[1] mas/yr
Parallax (π)	3.1874±0.0630 mas[1]
Distance	1,020 ± 20 ly (314 ± 6 pc)
Details
Mass	7.5±0.2[6] M☉
Radius	4.2[1] R☉
Luminosity	1,962[1] L☉
Surface gravity (log g)	3.99[1] cgs
Temperature	19,065[1] K
Metallicity [Fe/H]	−0.18[1] dex
Rotational velocity (v sin i)	5[7] km/s
Other designations
UW Arietis, BD+17°493, HD 19374, HIP 14514, HR 938, SAO 93284.[8]
Database references
SIMBAD	data

The claimed variability of 53 Arietis has not been confirmed.^{[4][9] [10]} It is a runaway star with a peculiar velocity of 48.1 km/s relative to its neighbors.^[6] The star was ejected from the Orion Nebula some 4–5 million years ago, possibly when an orbiting companion exploded as a supernova.^[11] Barnard's Loop is believed to be the remnant of the supernova that launched the star. ^[12]