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Eta Mensae

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Eta Mensae
Location of η Mensae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Mensa
Right ascension 04h 55m 11.20309s[1]
Declination −74° 56′ 12.6705″[1]
Apparent magnitude (V) 5.47[2]
Characteristics
Spectral type K4 III[3][4]
U−B color index +1.82[2]
B−V color index +1.52[2]
Astrometry
Proper motion (μ) RA: +28.27[1] mas/yr
Dec.: +61.52[1] mas/yr
Parallax (π)5.0299 ± 0.0998 mas[5]
Distance650 ± 10 ly
(199 ± 4 pc)
Absolute magnitude (MV)−1.08[6]
Details
Luminosity616[7] L
Surface gravity (log g)1.15[8] cgs
Temperature4,055[7] K
Metallicity [Fe/H]−0.17[8] dex
Other designations
η Men, CPD−75° 290, FK5 1138, HD 32440, HIP 22871, HR 1629, SAO 256145[9]
Database references
SIMBADdata

Eta Mensae, Latinized from η Mensae, is the Bayer designation for a solitary,[4] orange-hued star in the southern constellation of Mensa. This object has an apparent visual magnitude of 5.47,[2] which is sufficiently luminous to be faintly visible to the naked eye. Based upon an annual parallax shift of 4.88 mas as seen from Earth,[1] this star is located roughly 670 light years from the Sun.

This is an evolved K-type giant star with a stellar classification of K4 III.[3] It is radiating 616 times the Sun's luminosity from its photosphere at an effective temperature of 4,055 K.[7] The star displays an infrared excess that suggests the presence of circumstellar dust.[10][11] Eta Mensae is a probable member of the stream of stars associated with the Hyades cluster.[12]

References

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  1. ^ a b c d e 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. ^ a b c d 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. ^ a b 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. ^ a b 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ a b c McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  8. ^ a b Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
  9. ^ "eta Men". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-15.{{cite web}}: CS1 maint: postscript (link)
  10. ^ Kim, Sungsoo S.; et al. (April 2001), "Extent of Excess Far-Infrared Emission around Luminosity Class III Stars", The Astrophysical Journal, 550 (2): 1000–1006, arXiv:astro-ph/0012001, Bibcode:2001ApJ...550.1000K, doi:10.1086/319803, S2CID 118903790.
  11. ^ Zuckerman, B.; et al. (June 1995), "Luminosity Class III Stars with Excess Far-Infrared Emission", Astrophysical Journal Letters, 446: L79, Bibcode:1995ApJ...446L..79Z, doi:10.1086/187935.
  12. ^ Eggen, Olin J. (1996), "The Stellar Content of Star Stream I", Astronomical Journal, 111: 1615, Bibcode:1996AJ....111.1615E, doi:10.1086/117901.