Astronomy:Phi Centauri
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 13h 58m 16.27s[1] |
| Declination | −42° 06′ 02.7″[1] |
| Apparent magnitude (V) | +3.745[2] |
| Characteristics | |
| Spectral type | B2 IV[3] |
| U−B color index | −0.851[4] |
| B−V color index | −0.222[4] |
| Astrometry | |
| Radial velocity (Rv) | +5.3±1.5[5] km/s |
| Proper motion (μ) | RA: −22.77±0.15[1] mas/yr Dec.: −20.13±0.12[1] mas/yr |
| Parallax (π) | 6.21 ± 0.17[1] mas |
| Distance | 530 ± 10 ly (161 ± 4 pc) |
| Absolute magnitude (MV) | −2.20[2] |
| Details | |
| Mass | 8.5±0.3[3] M☉ |
| Radius | 4.19±0.35[6] R☉ |
| Luminosity | 4,000[7] L☉ |
| Surface gravity (log g) | 4.08±0.07[6] cgs |
| Temperature | 21,638±388[6] K |
| Rotational velocity (v sin i) | 79[8] km/s |
| Age | 18.0±3.2[3] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Phi Centauri, Latinized from φ Centauri, is a blue-white hued star in the southern constellation Centaurus. It is visible to the naked eye with an apparent visual magnitude of +3.7.[2] The annual parallax shift is 6.21 mas[1] as measured from Earth, which yields a distance estimate of around 530 light years. It is moving further from the Sun with a radial velocity of +5 km/s.[5]
This is a B-type subgiant star with a stellar classification of B2 IV.[3] It has no known companions, but does show radial velocity variations and higher order pulsations in the spectrum.[9] The star is just 18[3] million years old with 8.5[3] times the mass of the Sun and has 4.2[6] times the Sun's radius. It is radiating around 4,000[7] times the Sun's luminosity from its photosphere at an effective temperature of about 21,638 K.[6]
This star is a proper motion member of the Upper Centaurus–Lupus sub-group in the Scorpius–Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.[7]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V. Vizier catalog entry
- ↑ 2.0 2.1 2.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 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, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T.
- ↑ 4.0 4.1 Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement 15: 459, doi:10.1086/190168, Bibcode: 1968ApJS...15..459G.
- ↑ 5.0 5.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 6.0 6.1 6.2 6.3 6.4 Fitzpatrick, E. L.; Massa, D. (March 2005), "Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry", The Astronomical Journal 129 (3): 1642–1662, doi:10.1086/427855, Bibcode: 2005AJ....129.1642F.
- ↑ 7.0 7.1 7.2 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.
- ↑ Wolff, S. C. et al. (2007), "Rotational Velocities for B0-B3 Stars in Seven Young Clusters: Further Study of the Relationship between Rotation Speed and Density in Star-Forming Regions", The Astronomical Journal 133 (3): 1092–1103, doi:10.1086/511002, Bibcode: 2007AJ....133.1092W.
- ↑ Alecian, E. et al. (July 2014), "Discovery of new magnetic early-B stars within the MiMeS HARPSpol survey", Astronomy & Astrophysics 567: 19, doi:10.1051/0004-6361/201323286, A28, Bibcode: 2014A&A...567A..28A.
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