Rho Centauri

Rho Centauri

Location of ρ Centauri (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Centaurus
Right ascension	12^h 11^m 39.12805^s[1]
Declination	−52° 22′ 06.4067″[1]
Apparent magnitude (V)	+3.97[2]
Characteristics
Evolutionary stage	main sequence
Spectral type	B3 V[3]
U−B color index	−0.650[4]
B−V color index	−0.156±0.008[2]
Astrometry
Radial velocity (Rv)	+15.0±4.1[5] km/s
Proper motion (μ)	RA: −43.741[1] mas/yr Dec.: −11.771[1] mas/yr
Parallax (π)	11.8348 ± 0.3746 mas[1]
Distance	276 ± 9 ly (84 ± 3 pc)
Absolute magnitude (MV)	−1.33[2]
Details
Mass	6.6±0.1[6] M☉
Radius	3.8[7] R☉
Luminosity	810.42[2] L☉
Surface gravity (log g)	3.95[8] cgs
Temperature	19,500[8] K
Rotational velocity (v sin i)	147[9] km/s
Age	23.7±1.4[6] Myr
Other designations
Rho Cen, ρ Cen, CD−51°6455, HD 105937, HIP 59449, HR 4638, SAO 239737[10]
Database references
SIMBAD	data

Rho Centauri, Latinized from ρ Centauri, is a binary star[11] system in the southern constellation of Centaurus. It is visible to the naked eye as a blue-white hued point of light with a combined apparent visual magnitude of +3.97.[2] The system is located approximately 276 light years from the Sun based on parallax, and is drifting further away with a radial velocity of around +15 km/s.[5] It is a proper motion member of the Lower Centaurus–Crux sub-group in the Scorpius–Centaurus OB association, the nearest such association of co-moving massive stars to the Sun.[3]

The primary component of this system is a B-type main-sequence star with a stellar classification of B3 V.[3] It is about 24[6] million years old with a high rate of spin, showing a projected rotational velocity of 147 km/s.[9] It has 6.6[6] times the mass of the Sun and 3.8[7] times the Sun's radius. The star is radiating 810[2] times the luminosity of the Sun from its photosphere at an effective temperature of 19,500 K.[8]

The secondary companion is 1.1 magnitudes fainter than the primary, with a projected separation of 5.68 AU along a position angle of 19.72°, as of 2013.[11]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
3. de Geus, E. J.; et al. (June 1989), "Physical parameters of stars in the Scorpio-Centaurus OB association", Astronomy and Astrophysics, 216 (1–2): 44–61, Bibcode:1989A&A...216...44D
4. Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement, 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168.
5. Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
6. Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873
7. Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
8. Levenhagen, R. S.; Leister, N. V. (2006), "Spectroscopic analysis of southern B and Be stars", Monthly Notices of the Royal Astronomical Society, 371 (1): 252–262, arXiv:astro-ph/0606149, Bibcode:2006MNRAS.371..252L, doi:10.1111/j.1365-2966.2006.10655.x, S2CID 16492030.
9. Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory, University of Kyoto, Bibcode:1970crvs.book.....U.
10. "rho Cen -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-12-25.
11. Rizzuto, A. C.; et al. (December 2013), "Long-baseline interferometric multiplicity survey of the Sco-Cen OB association", Monthly Notices of the Royal Astronomical Society, 436 (2): 1694–1707, arXiv:1309.3811, Bibcode:2013MNRAS.436.1694R, doi:10.1093/mnras/stt1690.