Pi Centauri

π Centauri

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Centaurus
Right ascension	11^h 21^m 00.41^s[1]
Declination	−54° 29′ 27.7″[1]
Apparent magnitude (V)	+3.90
Characteristics
Spectral type	B5Vn
U−B color index	−0.59
B−V color index	−0.15
Variable type	none
Astrometry
Radial velocity (Rv)	+9 km/s
Proper motion (μ)	RA: -35.85 ± 0.34[1] mas/yr Dec.: -1.72 ± 0.27[1] mas/yr
Parallax (π)	9.12 ± 0.34[1] mas
Distance	360 ± 10 ly (110 ± 4 pc)
Absolute magnitude (MV)	−1.06
Orbit[2]
Primary	π Centauri A
Companion	π Centauri B
Period (P)	39.0 ± 0.19 yr
Semi-major axis (a)	0.2263 ± 0.0011"
Eccentricity (e)	0.8530 ± 0.0040
Inclination (i)	19.4 ± 4.9°
Longitude of the node (Ω)	327.8 ± 3.9°
Periastron epoch (T)	2010.410 ± 0.037
Argument of periastron (ω) (secondary)	340.3 ± 4.0°
Other designations
HR 4390, HD 98718, CP−53°4498, FK5 428, HIP 55425, SAO 238986, GC 15601, CCDM J11210-5429
Database references
SIMBAD	data

Pi Centauri (π Cen, π Centauri) is a binary star in the constellation Centaurus. It is approximately 360 light years from Earth.

Both components are blue-white B-type main sequence dwarfs. The primary π Centauri A, has an apparent magnitude of +4.3, while the apparent magnitude of its companion, π Centauri B, is +5.0. The two stars orbit around their common centre of mass once every 39 years.^[2] The semi-major axis of the companion is 0.23 arcseconds on the sky.

References

1. van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.Vizier catalog entry
2. Tokovinin, Andrei (2012). "Speckle Interferometry and Orbits of "Fast" Visual Binaries". The Astronomical Journal. 144 (2). 56. arXiv:1206.1882. Bibcode:2012AJ....144...56T. doi:10.1088/0004-6256/144/2/56.