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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 06h 52m 18.05045s[1] |
| Declination | −05° 10′ 25.36617″[1] |
| Apparent magnitude (V) | 6.58[2] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | K3.5 V[3] |
| B−V color index | 1.071±0.008[2] |
| Astrometry | |
| Radial velocity (Rv) | −7.20±0.15[4] km/s |
| Proper motion (μ) | RA: −543.616[1] mas/yr Dec.: −3.491[1] mas/yr |
| Parallax (π) | 114.2968 ± 0.0465 mas[1] |
| Distance | 28.54 ± 0.01 ly (8.749 ± 0.004 pc) |
| Absolute magnitude (MV) | 6.87[5] |
| Details | |
| Mass | 0.79[6] M☉ |
| Radius | 0.73+0.01 −0.02[1] R☉ |
| Luminosity | 0.225[1] L☉ |
| Surface gravity (log g) | 4.64[6] cgs |
| Temperature | 4,712±8.5[7] K |
| Metallicity [Fe/H] | +0.01[8] dex |
| Rotational velocity (v sin i) | 5.5[6] km/s |
| Age | 1.88[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | A |
| B | |
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
edit- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ "HD 50281". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-06-06.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.