Kappa Mensae

Kappa Mensae, Latinized from κ Mensae, is a solitary^[14] star in the southern circumpolar constellation Mensa. Its distance of 296 light years^[1] based on its parallax shift gives it an apparent magnitude of 5.45,^[2] making it faintly visible to the naked eye. However, it is receding from the Sun with a heliocentric radial velocity of 9.5 km/s.^[6]

κ Mensae

Location of κ Mensae (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Mensa
Right ascension	05h 50m 16.7857s[1]
Declination	−79° 21′ 40.900″[1]
Apparent magnitude (V)	5.45 ± 0.01[2]
Characteristics
Evolutionary stage	main sequence[3]
Spectral type	B9 V[4]
U−B color index	−0.24[5]
B−V color index	−0.08[5]
Astrometry
Radial velocity (Rv)	9.5 ± 2[6] km/s
Proper motion (μ)	RA: −4.815 mas/yr[1] Dec.: +66.518 mas/yr[1]
Parallax (π)	11.018 ± 0.0604 mas[1]
Distance	296 ± 2 ly (90.8 ± 0.5 pc)
Absolute magnitude (MV)	+0.78[7]
Details
Mass	3.44[8] M☉
Radius	1.95±0.09[9] R☉
Luminosity	66.4+2.6 −2.5[3] L☉
Surface gravity (log g)	4.21[8] cgs
Temperature	10,965±50[3] K
Metallicity [Fe/H]	0.00[10] dex
Rotational velocity (v sin i)	290[11] km/s
Age	115[8] Myr
Other designations
κ Mensae, 32 G. Mensae, CPD−79° 202, HD 40953, HIP 27566, HR 2125, SAO 256248[12][13]
Database references
SIMBAD	data

Kappa Mensae has a stellar classification of B9 V,^[4] indicating that it is an ordinary B-type main-sequence star. At present it has 3.44 times the mass of the Sun^[8] and a diameter of 1.95 R_☉.^[9] It radiates at 66^[3] times the luminosity from its photosphere at an effective temperature of 10,965 K,^[3] giving it a bluish white hue. The star is very young, aged 115 million years,^[8] having completed only 33.7% of its main sequence lifetime.^[3] Kappa Mensae has a high rate of spin, rotating with a projected rotational velocity of 290 km/s.^[11]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
2. Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
3. Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. ISSN 0004-6361. S2CID 55586789.
4. Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0. Bibcode:1975mcts.book.....H.
5. Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (January 1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
6. Evans, D. S. (1967). "The Revision of the General Catalogue of Radial Velocities". International Astronomical Union. 30: 57. Bibcode:1967IAUS...30...57E.
7. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. ISSN 1063-7737. S2CID 119257644.
8. David, Trevor J.; Hillenbrand, Lynne A. (12 May 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. ISSN 1538-4357.
9. Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. ISSN 0004-6361.
10. Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. ISSN 0320-0108. S2CID 255201789.
11. Levato, H.; Grosso, M. (June 2004). "New Projected Rotational Velocities of All Southern B-type Stars of the Bright Star Catalogue". Astronomical Society of the Pacific. 215: 51. Bibcode:2004IAUS..215...51L.
12. "kap Men". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved June 15, 2022.
13. Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
14. Eggleton, P. P.; Tokovinin, A. A. (11 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. eISSN 1365-2966. ISSN 0035-8711.