Astronomy:Delta Mensae

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Short description: Binary star system in the constellation Mensa
Delta Mensae
Observation data
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[1] mas
Distance468 ± 8 ly
(144 ± 2 pc)
Absolute magnitude (MV)0.34[5]
Details
δ Men A
Radius13.12+0.52
−0.46
[1] R
Luminosity111.7±2.2[1] L
Temperature5,180+94
−99
[1] K
Rotational velocity (v sin i)4.7±0.2[5] km/s
Other designations
δ Men, CPD−80° 116, FK5 166, HD 28525, HIP 20049, HR 1426, SAO 258372[6]
Database references
SIMBADdata

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.

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

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  3. 3.0 3.1 3.2 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, doi:10.1086/313152, Bibcode1998ApJS..119...83P. 
  4. 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, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  5. 5.0 5.1 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, doi:10.1051/0004-6361/201118724, Bibcode2012A&A...542A.116A. 
  6. "del Men". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=del+Men. 
  7. 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  8. van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 

Coordinates: Sky map 04h 17m 59.1s, −80° 12′ 50″