HD 117440

d Centauri A/B

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Centaurus
Right ascension	13h 31m 02.66s
Declination	−39° 24′ 26.3″
Apparent magnitude (V)	+4.5/+4.7
Characteristics
Spectral type	G8III/G9III
U−B color index	+1.03
B−V color index	+1.17
Variable type	none
Astrometry
Radial velocity (Rv)	−2 km/s
Proper motion (μ)	RA: -15.67 ± 0.47 mas/yr Dec.: -10.49 ± 0.31 mas/yr
Parallax (π)	3.60 ± 0.49 mas
Distance	approx. 900 ly (approx. 280 pc)
Absolute magnitude (MV)	−3.4/−3.2
Other designations
HR 5089, HD 117440, CD−38°8592, HIP 65936, SAO 204545, GC 18254, CCDM J13310-3924
Database references
SIMBAD	data

HD 117440, also known by its Bayer designation d Centauri (d Cen), is a binary star in the constellation Centaurus. It is approximately 900 light years from Earth.

Both components are yellow G-type giant stars. The primary, d Centauri A, has an apparent magnitude of +4.5, while the secondary, d Centauri B, has an apparent magnitude of +4.7. The two stars orbit around their common centre of mass once every 78.7 years and the secondary has a semi-major axis of 0.165 arcseconds.