21 Lyncis

21 Lyncis

21 Lyncis (center) in optical light
Observation data Epoch J2000      Equinox J2000
Constellation	Lynx
Right ascension	07^h 26^m 42.85187^s[1]
Declination	+49° 12′ 41.4907″[1]
Apparent magnitude (V)	4.61[2]
Characteristics
Evolutionary stage	main sequence
Spectral type	A0.5Vs[3]
B−V color index	−0.001±0.002[2]
Astrometry
Radial velocity (Rv)	+26.8±0.1[2] km/s
Proper motion (μ)	RA: −10.22[1] mas/yr Dec.: −49.29[1] mas/yr
Parallax (π)	11.92 ± 0.24 mas[1]
Distance	274 ± 6 ly (84 ± 2 pc)
Absolute magnitude (MV)	−0.01[2]
Details
Mass	2.22[4] M☉
Luminosity	102.01[2] L☉
Temperature	9,692±330[4] K
Rotational velocity (v sin i)	18[4] km/s
Age	272[4] Myr
Other designations
21 Lyn, BD+49° 1623, FK5 2572, HD 58142, HIP 36145, HR 2818, SAO 41764[5]
Database references
SIMBAD	data

21 Lyncis is a single[6] star in the northern constellation of Lynx. It is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.61.[2] The star is located at a distance of about 274 light years away from the Sun, based on parallax.[1] It is moving further away from the Earth with a heliocentric radial velocity of around +27 km/s.[2]

This object is an ordinary A-type main-sequence star with a stellar classification of A0.5Vs,[3] where the 's' suffix indicates "sharp" lines in the spectrum, usually due to slow rotation. It is about 272[4] million years old with a projected rotational velocity of 18 km/s.[4] The star has 2.22[4] times the mass of the Sun and is radiating 102[2] times the luminosity of the Sun from its photosphere at an effective temperature of 9,692 K.[4]

References

1. van Leeuwen, F. (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, S2CID 18759600.
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. Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182
4. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
5. "21 Lyn". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-06-05.
6. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.