Iota Mensae is a single star about 880 light years away in the faint constellation Mensa. It has a very slightly variableapparent 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.[12] Its brightness varies by a few hundredths of a magnitude. Its period was initially measured at 2.6 days,[13] 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.[2]
^ abcSamus, 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.
^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.
^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. ISSN0004-6361.
^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.