Xi1 Centauri

For other star systems with this Bayer designation, see Xi Centauri.

Xi¹ Centauri, Latinized from ξ¹ Centauri, is a solitary^[11] star in the southern constellation of Centaurus. It is visible to the naked eye with an apparent visual magnitude of +4.83.^[2] With an annual parallax shift of 14.79 mas,^[1] it is located around 221 light years from the Sun. At that distance, the apparent visual magnitude of the star is diminished by an interstellar extinction factor of 0.10^[12] due to intervening dust. Just 17 arc minutes to the east of Xi¹ Centauri lies the galaxy NGC 4945.^[13]

ξ¹ Centauri

Location of ξ1 Centauri (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Centaurus
Right ascension	13h 03m 33.30528s[1]
Declination	−49° 31′ 38.1518″[1]
Apparent magnitude (V)	+4.83[2]
Characteristics
Spectral type	A0 V[3]
U−B color index	+0.014[2]
B−V color index	+0.030[2]
Astrometry
Radial velocity (Rv)	0.00±3.70[4] km/s
Proper motion (μ)	RA: −47.55[1] mas/yr Dec.: −11.52[1] mas/yr
Parallax (π)	14.79±0.27 mas[1]
Distance	221 ± 4 ly (68 ± 1 pc)
Absolute magnitude (MV)	+0.68[5]
Details[6]
Mass	2.39 M☉
Radius	2.7[7] R☉
Luminosity	43.2[8] L☉
Surface gravity (log g)	4.11±0.14 cgs
Temperature	10,462±356 K
Rotational velocity (v sin i)	185[9] km/s
Age	125 Myr
Other designations
ξ1 Cen, CD−48° 7887, HD 113314, HIP 63724, HR 4933, SAO 223870.[10]
Database references
SIMBAD	data

ξ¹ Cen is the brightest star in the picture, at the right of the galaxy NGC 4945.

This is an A-type main sequence star with a stellar classification of A0 V.^[3] It is about 125 million years old^[6] with a relatively high rate of spin, having a projected rotational velocity of 185 km/s.^[9] The star has an estimated 2.4 times the mass of the Sun^[6] and about 2.7 times the Sun's radius.^[7] It is radiating 43 times the solar luminosity^[8] from its outer atmosphere at an effective temperature of 10,462 K.^[6]