Delta Mensae, Latinized from δ Mensae, is a binary star[7] system in the southern constellation of Mensa. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.69.[2] Based upon an annual parallax shift of 7.70 mas as seen from the Earth,[8] it is 420 light years from the Sun.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Mensa |
| Right ascension | 04h 17m 59.27258s[1] |
| Declination | −80° 12′ 50.5073″[1] |
| Apparent magnitude (V) | 5.69[2] |
| Characteristics | |
| Spectral type | K2/3 III + A9[3] |
| U−B color index | +0.53[2] |
| B−V color index | +0.84[2] |
| Astrometry | |
| Radial velocity (Rv) | −20.0±4.3[4] km/s |
| Proper motion (μ) | RA: +27.719[1] mas/yr Dec.: +61.679[1] mas/yr |
| Parallax (π) | 6.9662 ± 0.1168 mas[1] |
| Distance | 468 ± 8 ly (144 ± 2 pc) |
| Absolute magnitude (MV) | 0.34[5] |
| Details | |
| δ Men A | |
| Radius | 13.12+0.52 −0.46[1] R☉ |
| Luminosity | 111.7±2.2[1] L☉ |
| Temperature | 5,180+94 −99[1] K |
| Rotational velocity (v sin i) | < 4.7±0.2[5] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary, designated component A, is a K-type giant star with a stellar classification of K2/3 III.[3] With the supply of hydrogen at its core exhausted, it has cooled and expanded to 13 times the radius of the Sun. The star is radiating 112 times the Sun's luminosity from its photosphere at an effective temperature of 5,180 K.[1] Its companion, component B, is an A-type star about 0.9 magnitudes fainter than the primary.[3]
References
edit- ^ a b c d e f g h i 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.
- ^ 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.
- ^ a b c Parsons, Sidney B.; Ake, Thomas B. (November 1998), "Ultraviolet and Optical Studies of Binaries with Luminous Cool Primaries and Hot Companions. V. The Entire IUE Sample", The Astrophysical Journal Supplement Series, 119 (1): 83–104, Bibcode:1998ApJS..119...83P, doi:10.1086/313152.
- ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID 53666672.
- ^ "del Men". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-16.
{{cite web}}: CS1 maint: postscript (link) - ^ 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.
- ^ 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.