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ι Mensae

Location of ι Mensae (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Mensa
Right ascension	05 35 36.1787
Declination	−78° 49′ 15.129″
Apparent magnitude (V)	6.00 - 6.05
Characteristics
Spectral type	B8 III
B−V color index	−0.022
Variable type	Ellipsoidal?
Astrometry
Radial velocity (Rv)	12.6±4.3 km/s
Proper motion (μ)	RA: +5.547 mas/yr Dec.: +25.710 mas/yr
Parallax (π)	3.7076 ± 0.1819 mas
Distance	880 ± 40 ly (270 ± 10 pc)
Absolute magnitude (MV)	−1.03
Details
Mass	3.6 M☉
Radius	9.5 R☉
Luminosity	301 L☉
Surface gravity (log g)	3.4 cgs
Temperature	11,272±264 K
Metallicity	+0.13 dex
Age	203 Myr
Other designations
ι Men, CD−78°216, HD 38602, HIP 26264, HR 1991, SAO 256214
Database references
SIMBAD	data

Iota Mensae is a single star about 880 light years away in the faint constellation Mensa. It has a very slightly variable apparent magnitude of 6.0, making it visible with the naked eye under good skies.

Iota Mensae has a spectral type of B8III, indicating that it has exhausted hydrogen at its core and expanded away from the main sequence. It is about 3.6 times the mass (M_☉), 301 times as luminous, and has swollen to 9.5 times the radius of the Sun (R_☉). It is calculated to be 314 million years old.

It has been catalogued as a chemically peculiar star with abnormally strong lines of silicon in its spectrum but this classification is now considered doubtful. Its brightness varies by a few hundredths of a magnitude. Its period was initially measured at 2.6 days, but this is now considered to be a period of 5.3 days with primary and secondary minima of a similar depth. The variability is thought to be due to the rotation of the star.

References

1. ^ Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
2. ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
3. Houk, Nancy (1975). "Michigan catalogue of two-dimensional spectral types for the HD stars". University of Michigan Catalogue of Two-Dimensional Spectral Types for the Hd Stars. Volume I. Declinations -90_ to -53_Ƒ0. 1. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode:1975mcts.book.....H.
4. 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.
5. Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. ISSN 1063-7737. S2CID 119231169.
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. Lafrasse, Sylvain; Mella, Guillaume; Bonneau, Daniel; Duvert, Gilles; Delfosse, Xavier; Chesneau, Olivier; Chelli, Alain (16 July 2010). "Building the 'JMMC Stellar Diameters Catalog' using SearchCal". Optical and Infrared Interferometry II. Vol. 7734. pp. 77344E. arXiv:1009.0137. Bibcode:2010SPIE.7734E..4EL. doi:10.1117/12.857024. S2CID 32097037.
8. Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
9. Anders, F.; et al. (February 2022). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5". Astronomy & Astrophysics. 658: A91. arXiv:2111.01860. Bibcode:2022A&A...658A..91A. doi:10.1051/0004-6361/202142369. eISSN 1432-0746. ISSN 0004-6361.
10. "Iota Men". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-18.
11. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 14 September 2024.
12. Renson, P.; Manfroid, J. (2009). "Catalogue of Ap, HGMN and Am stars". Astronomy and Astrophysics. 498 (3): 961. Bibcode:2009A&A...498..961R. doi:10.1051/0004-6361/200810788.
13. Grønbech, B.; Naqvi, S. I. H. (1976). "HR 1991. A new variable B star". Astronomy and Astrophysics Supplement Series. 26: 147. Bibcode:1976A&AS...26..147G.

v t e Constellation of Mensa
List of stars in Mensa
Stars	Bayer α β γ δ ε ζ η θ ι κ λ μ ν ξ π Variable W TU TY TZ UX YY AH AO HR 1109 1154 1531 1606 1682 1700 HD 35184 38283 (Bubup) 39194 42936 268835 Other OGLE-LMC-CEP0227 R71 WISE 0535−7500
Exoplanets π Mensae b c d HD 38283 b (Yanyan)
Star clusters NGC 1943 NGC 1959 NGC 1986 NGC 1987 NGC 2000
Nebulae Henize 206 NGC 2122
Galaxies	NGC 2012 2144 Other Large Magellanic Cloud (mostly in Dorado, partly in Hydrus) PKS 0637-752
Category

• Mensa (constellation)
• Bayer objects
• Hipparcos objects
• Bright Star Catalogue objects
• Henry Draper Catalogue objects
• B-type giants
• Rotating ellipsoidal variables
• Durchmusterung objects