Pollux (starn)

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Pollux
Gemini constellation map.svg
The poseetion o Pollux within the constellation o Gemini.
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Gemini
Richt ascension 07h 45m 18.94987s[1]
Declination +28° 01′ 34.3160″[1]
Apparent magnitude (V) 1.14[2]
Characteristics
Spectral type K0 III[3]
U−B colour index +0.86[2]
B−V colour index +1.00[2]
Variable type Suspected
Astrometry
Radial velocity (Rv) +3.23[4] km/s
Proper motion (μ) RA: –626.55[1] mas/yr
Dec.: –45.80[1] mas/yr
Parallax (π) 96.54 ± 0.27[1] mas
Distance 33.78 ± 0.09 ly
(10.36 ± 0.03 pc)
Absolute magnitude (MV) +1.08 ± 0.02[5]
Details
Mass 2.04 ± 0.3[6] M
Radius 8.8 ± 0.1[7] R
Luminosity 43[8] L
Surface gravity (log g) 2.685 ± 0.09[7]
Temperatur 4,666 ± 95[7] K
Metallicity [Fe/H] –0.07 to +0.19[7] dex
Rotation 558 days[9]
Rotational velocity (v sin i) 2.8[10] km/s
Age 724[11] Myr
Ither designations
Beta Geminorum, 78 Geminorum, BD+28°1463, GCTP 1826.00, Gliese 286, HD 62509, HIP 37826, HR 2990, LFT 548, LHS 1945, LTT 12065, SAO 79666.[12]
Database references
SIMBAD data
ARICNS data

Pollux (β Gem, β Geminorum, Beta Geminorum) is a starn in the northren constellation o Gemini, the Twins. It is an evolved giant star wi an orange hue. At an apparent visual magnitude o 1.1,[2] Pollux is the brichtest starn in the constellation; brichter even than its neighbor Castor (Alpha Geminorum). Parallax measurments made wi the Hipparcos astrometry satellite[13][14] place it at a distance o aboot 33.78 light-years (10.36 parsecs) frae Yird[1]. Syne 1943, the spectrum o this starn has served as ane o the stable anchor pynts bi which ither starns are classified.[15] In 2006, Pollux wis confirmed tae hae an extrasolar planet orbitin it.[7]

References[eedit | eedit soorce]

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (November 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 
  2. 2.0 2.1 2.2 2.3 Lee, T. A. (October 1970), "Photometry of high-luminosity M-type stars", Astrophysical Journal 162: 217, Bibcode:1970ApJ...162..217L, doi:10.1086/150648 
  3. Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics 11: 29, Bibcode:1973ARA&A..11...29M, doi:10.1146/annurev.aa.11.090173.000333 
  4. Famaey, B. et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272 
  5. Carney, Bruce W. et al. (March 2008), "Rotation and Macroturbulence in Metal-Poor Field Red Giant and Red Horizontal Branch Stars", The Astronomical Journal 135 (3): 892–906, arXiv:0711.4984, Bibcode:2008AJ....135..892C, doi:10.1088/0004-6256/135/3/892 
  6. Aurière, M. et al. (September 2009), "Discovery of a weak magnetic field in the photosphere of the single giant Pollux", Astronomy and Astrophysics 504 (1): 231–237, arXiv:0907.1423, Bibcode:2009A&A...504..231A, doi:10.1051/0004-6361/200912050 
  7. 7.0 7.1 7.2 7.3 7.4 Hatzes, A. P. et al. (2006), "Confirmation of the planet hypothesis for the long-period radial velocity variations of β Geminorum", Astronomy and Astrophysics 457: 335–341, arXiv:astro-ph/0606517, Bibcode:2006A&A...457..335H, doi:10.1051/0004-6361:20065445 
  8. Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics 352: 495–507, Bibcode:1999A&A...352..495M 
  9. Koncewicz, R.; Jordan (January 2007), "OI line emission in cool stars: calculations using partial redistribution", Monthly Notices of the Royal Astronomical Society 374 (1): 220–231, Bibcode:2007MNRAS.374..220K, doi:10.1111/j.1365-2966.2006.11130.x 
  10. Massarotti, Alessandro et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209 
  11. Takeda, Yoichi; Sato, Bun'ei; Murata, Daisuke (August 2008), "Stellar parameters and elemental abundances of late-G giants", Publications of the Astronomical Society of Japan 60 (4): 781–802, arXiv:0805.2434, Bibcode:2008PASJ...60..781T 
  12. "POLLUX -- Variable Star", SIMBAD (Centre de Données astronomiques de Strasbourg), retrieved 2012-01-14 
  13. Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; et al. (July 1997), "The Hipparcos Catalogue", Astronomy and Astrophysics 323: L49–L52, Bibcode:1997A&A...323L..49P 
  14. Perryman, Michael (2010), The Making of History's Greatest Star Map, Heidelberg: Springer-Verlag, doi:10.1007/978-3-642-11602-5 
  15. Garrison, R. F. (December 1993), "Anchor Points for the MK System of Spectral Classification", Bulletin of the American Astronomical Society 25: 1319, Bibcode:1993AAS...183.1710G, retrieved 2012-02-04