Beta Mensae

Beta Mensae, Latinized from β Mensae, is the third-brightest star in the constellation of Mensa. Despite this, it is only faintly visible to the naked eye, appearing as a dim, yellow-hued point of light with an apparent visual magnitude of 5.31.^[2] The star is positioned near the southwest edge of the Large Magellanic Cloud, but it does not form part of this much more distant satellite galaxy. Based upon an annual parallax shift of just 4.11 mas as seen from the Earth,^[8] the star is located at a distance of roughly 790 light years from the Sun. It is moving closer with a heliocentric radial velocity of −11 km/s.^[4]

β Mensae

Location of β Mensae (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Mensa
Right ascension	05h 02m 42.99847s[1]
Declination	−71° 18′ 51.4765″[1]
Apparent magnitude (V)	5.31[2]
Characteristics
Spectral type	G8 III[3]
U−B color index	+0.77[2]
B−V color index	+1.00[2]
Astrometry
Radial velocity (Rv)	−11.40[4] km/s
Proper motion (μ)	RA: −4.368[1] mas/yr Dec.: +10.815[1] mas/yr
Parallax (π)	4.9368 ± 0.0810 mas[1]
Distance	660 ± 10 ly (203 ± 3 pc)
Absolute magnitude (MV)	−1.62[5]
Details
Mass	3.58[4] M☉
Radius	25.85+0.69 −0.62[1] R☉
Luminosity	345±7[1] L☉
Surface gravity (log g)	2.54±0.11[6] cgs
Temperature	5,088±44[6] K
Metallicity [Fe/H]	+0.00±0.04[6] dex
Age	270[4] Myr
Other designations
β Men, CPD−71° 309, FK5 2380, GC 6232, HD 33285, HIP 23467, HR 1677, SAO 256154, PPM 368632[7]
Database references
SIMBAD	data

This is a solitary,^[9] G-type giant star with a stellar classification of G8 III.^[3] It is around 270 million years old with 3.6 times the mass of the Sun.^[4] Having exhausted the supply of hydrogen at its core, it has expanded to 26^[1] times the Sun's radius. Beta Mensae is radiating 513^[4] times the Sun's luminosity from its photosphere at an effective temperature of about 5,088 K.^[6]

References

1. 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. Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
3. Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
4. Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 23, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114, 88.
5. 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.
6. Alves, S.; et al. (April 2015), "Determination of the spectroscopic stellar parameters for 257 field giant stars", Monthly Notices of the Royal Astronomical Society, 448 (3): 2749–2765, arXiv:1503.02556, Bibcode:2015MNRAS.448.2749A, doi:10.1093/mnras/stv189.
7. "bet Men". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-16.{{cite web}}: CS1 maint: postscript (link)
8. 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.
9. 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.