D Centauri

For d Centauri, see HD 117440.

D Centauri is a double star in the southern constellation of Centaurus.^[8] The system is faintly visible to the naked eye as a point of light with a combined apparent magnitude of +5.31;^[1] the two components are of magnitude 5.78 and 6.98, respectively.^[3] It is located at a distance of approximately 610 light years from the Sun based on parallax, and is drifting further away with a radial velocity of ~10 km/s.^[6]

D Centauri

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Centaurus[1]
Right ascension	12h 14m 02.697s[2]
Declination	−45° 43′ 26.10″[2]
Apparent magnitude (V)	+5.31[1] (5.78 + 6.98)[3]
Characteristics
Spectral type	K3III[4] (K4IIIab + K2IIIb)[5]
U−B color index	+1.82/1.19[5]
B−V color index	+1.400±0.003[1]/1.21[5]
Astrometry
A
Radial velocity (Rv)	+10.27±0.68[6] km/s
Proper motion (μ)	RA: −37.186[6] mas/yr Dec.: 6.606[6] mas/yr
Parallax (π)	5.3350±0.1399 mas[6]
Distance	610 ± 20 ly (187 ± 5 pc)
Absolute magnitude (MV)	−0.88[1]
B
Proper motion (μ)	RA: −33.604[7] mas/yr Dec.: 5.434[7] mas/yr
Parallax (π)	4.9297±0.0550 mas[7]
Distance	662 ± 7 ly (203 ± 2 pc)
Details
A
Radius	42.8+1.1 −2.13[6] R☉
Luminosity	434±13[6] L☉
Temperature	4,026+104 −50[6] K
B
Radius	13.5+1.7 −1.9[7] R☉
Luminosity	90.5±1.4[7] L☉
Temperature	4,853+275 −392[7] K
Other designations
D Cen, CD−45°7630, GC 16703, HD 106321, HIP 59654, HR 4652, SAO 223297, CCDM J12140-4543[8]
Database references
SIMBAD	data

The dual nature of this star was announced by C. Rumker in 1837. As of 2015, the pair had an angular separation of 2.70″ along a position angle of 242°.^[3] This orange-hued double has a combined stellar classification of K3III,^[4] matching an aging giant star that has exhausted the supply of hydrogen at its core. In 1984, C. J. Corbally found a class of K4IIIab for the primary and K2IIIb for the fainter secondary.^[5]