HD 50281 is a star in the equatorial constellation of Monoceros. It is orange in hue with an apparent visual magnitude of 6.58,[2] which lies at or below the typical limit of visibility to the naked eye. The star is located at a distance of 28.5 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −7.2 km/s.[4]

This object is an ordinary K-type main-sequence star with a stellar classification of K3.5 V.[3] It is nearly two billion years old and is spinning with a projected rotational velocity of 5.5 km/s.[6] The metallicity of this star – what astronomers term the abundance of elements with atomic numbers greater than helium – is near solar. The star has 79%[6] of the mass of the Sun and 73%[1] of the Sun's radius. It is radiating 22.5%[1] of the luminosity of the Sun from its photosphere at an effective temperature of 4,712 K.[7]

A magnitude 10.16 common proper motion companion,[10] designated component B, is located at an angular separation of 58.8″ along a position angle of 181° from the primary, as of 2015.[10] This is a suspected binary star system[11] with components of individual visual magnitude 10.6 and 11.1,[10] and a class of M2.5 V.[12] The coordinates of this companion are a source of X-ray emission.[13] A third companion, magnitude 14.04 component C, lies at a separation of 9.6″ from component B.[10]

References

  1. ^ a b c d e f g h i 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. ^ a b c 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. ^ a b Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
  4. ^ a b Bailer-Jones, C.A.L.; et al. (2018). "New stellar encounters discovered in the second Gaia data release". Astronomy & Astrophysics. 616: A37. arXiv:1805.07581. Bibcode:2018A&A...616A..37B. doi:10.1051/0004-6361/201833456. S2CID 56269929.
  5. ^ Holmberg, J.; et al. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics. 501 (3): 941–947. arXiv:0811.3982. Bibcode:2009A&A...501..941H. doi:10.1051/0004-6361/200811191. S2CID 118577511.
  6. ^ a b c d e f Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. S2CID 119511744. 21.
  7. ^ a b Kovtyukh, V. V.; et al. (2003). "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios". Astronomy and Astrophysics. 411 (3): 559–564. arXiv:astro-ph/0308429. Bibcode:2003A&A...411..559K. doi:10.1051/0004-6361:20031378. S2CID 18478960.
  8. ^ Rojas-Ayala, Bárbara; et al. (April 2012). "Metallicity and Temperature Indicators in M Dwarf K-band Spectra: Testing New and Updated Calibrations with Observations of 133 Solar Neighborhood M Dwarfs" (PDF). The Astrophysical Journal. 748 (2): 93. arXiv:1112.4567. Bibcode:2012ApJ...748...93R. doi:10.1088/0004-637X/748/2/93. S2CID 41902340.
  9. ^ "HD 50281". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-06-06.
  10. ^ a b c d Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
  11. ^ Mason, Brian D.; et al. (May 2018). "Speckle Interferometry of Red Dwarf Stars". The Astronomical Journal. 155 (5): 14. arXiv:1804.07845. Bibcode:2018AJ....155..215M. doi:10.3847/1538-3881/aab9b8. S2CID 119267352. 215.
  12. ^ Kirkpatrick, J. D.; et al. (1991). "A standard stellar spectral sequence in the red/near-infrared - Classes K5 to M9". Astrophysical Journal Supplement Series. 77: 417. Bibcode:1991ApJS...77..417K. doi:10.1086/191611.
  13. ^ Johnson, H. M. (April 1986). "An Unbiased X-Ray Sampling of Stars within 25 Parsecs of the Sun". Astrophysical Journal. 303: 470. Bibcode:1986ApJ...303..470J. doi:10.1086/164092. hdl:2060/19860004737.
Allikas: http://en.wikipedia.org/wiki/HD_50281
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