Theta Mensae

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θ Mensae
Mensa IAU.svg
Red circle.svg
Location of θ Mensae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Mensa
Right ascension 06h 56m 34.47s[1]
Declination −79° 25′ 12.69″[1]
Apparent magnitude (V) 5.449±0.009[2]
Characteristics
Spectral type B9.5/A0 III/IV[3]
B−V color index 0.041±0.003[4]
Astrometry
Radial velocity (Rv)6.0±7.4[5] km/s
Proper motion (μ) RA: -2.172[1] mas/yr
Dec.: -1.176[1] mas/yr
Parallax (π)8.2527 ± 0.1059[1] mas
Distance395 ± 5 ly
(121 ± 2 pc)
Absolute magnitude (MV)0.28[4]
Details
Mass2.48+0.29
−0.36[6] M☉
Radius3.93+0.12
−0.11[6] R☉
Luminosity124+8
−6[6] L☉
Surface gravity (log g)3.64±0.06[6] cgs
Temperature9717+125
−104[6] K
Metallicity [Fe/H]-0.02[7] dex
Rotational velocity (v sin i)209[8] km/s
Age266±4[9] Myr
Other designations
θ Mensae, HD 54239, HIP 33384, HR 2689, SAO 256355[10]
Database references
SIMBADdata

θ Mensae, latinized to Theta Mensae, is a solitary[11] star located in the constellation Mensa. With an apparent magnitude of 5.45, it is visible to the naked eye under good conditions. Theta Mensae is located 395 light years away from the Solar System, but is drifting away with a radial velocity of 6 km/s.

Properties[]

This star has a classification of “B9.5/A0 III/IV”, which suggests it has the characteristics of a B9.5 and A0 star, and the properties of a giant star and a subgiant. However, some sources give is a classification of B9.5V, suggesting it is a B9.5 main sequence star.[12] Theta Mensae has 2.48 times the Sun’s mass, but has expanded to 3.93 times the radius. It radiates at 124 solar luminosities, and has an effective temperature of 9,717 K, which gives it a bluish-white hue. Theta Mensae rotates rapidly with a projected rotational velocity of 209 km/s despite its advanced age of 166 million years.

References[]

  1. ^ a b c d 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. ^ 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. ^ 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_f0". University of Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume I. Declinations -90_ to -53_f0., by Houk, N.; Cowley, A. P.. Ann Arbor, MI (USA): Department of Astronomy, University of Michigan, 19 + 452 P. Bibcode:1975mcts.book.....H.
  4. ^ a b Anderson, E.; Francis, Ch. (2012-05-01). "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.
  5. ^ Kharchenko, N. V.; Scholz, R.-D.; Piskunov, A. E.; Röser, S.; Schilbach, E. (2007-11-01). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889–896. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. ISSN 0004-6337. S2CID 119323941.
  6. ^ a b c d e Stassun, Keivan G.; Oelkers, Ryan J.; Paegert, Martin; Torres, Guillermo; Pepper, Joshua; De Lee, Nathan; Collins, Kevin; Latham, David W.; Muirhead, Philip S.; Chittidi, Jay; Rojas-Ayala, Bárbara (2019-10-01). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. hdl:1721.1/124721. ISSN 0004-6256. S2CID 166227927.
  7. ^ Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevic, G.; Monari, G.; Cantat-Gaudin, T. (2019-08-01). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. ISSN 0004-6361. S2CID 131780028.
  8. ^ Levato, H.; Grosso, M. (2004-06-01). "New Projected Rotational Velocities of All Southern B-type Stars of the Bright Star Catalogue". 215: 51. Bibcode:2004IAUS..215...51L. Cite journal requires |journal= (help)
  9. ^ Zorec, J.; Royer, F. (2012-01-01). "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.
  10. ^ SIMBAD. Centre de données astronomiques de Strasbourg http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+20794. Missing or empty |title= (help)
  11. ^ Eggleton, P. P.; Tokovinin, A. A. (2008-09-01). "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. ISSN 0035-8711. S2CID 14878976.
  12. ^ Buscombe, William (1969). "Line strengths for southern OB stars-II. Observations with moderate dispersion". Monthly Notices of the Royal Astronomical Society. 144: 31–39. Bibcode:1969MNRAS.144...31B. doi:10.1093/mnras/144.1.31. ISSN 0035-8711.
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