Delta Mensae

Delta Mensae
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Mensa
Right ascension	04h 17m 59.2718s
Declination	−80° 12′ 50.511″
Apparent magnitude (V)	5.69
Characteristics
Spectral type	K2/3 III + A9
U−B color index	+0.53
B−V color index	+0.84
Astrometry
Radial velocity (Rv)	−20.0±4.3 km/s
Proper motion (μ)	RA: +27.53 mas/yr ; Dec.: +61.56 mas/yr
Parallax (π)	7.70 ± 0.27 mas
Distance	420 ± 10 ly ; (130 ± 5 pc)
Absolute magnitude (MV)	0.34
Details
δ Men A
Radius	14 R☉
Luminosity	92 L☉
Temperature	5,183 K
Rotational velocity (v sin i)	< 4.7±0.2 km/s
Other designations
	δ Men, CPD−80° 116, FK5 166, HD 28525, HIP 20049, HR 1426, SAO 258372
Database references
SIMBAD	data

Delta Mensae (δ Mensae) is a binary star^[9] 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,^[1] 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] The measured angular diameter of this star is 1.00±0.01 mas,^[10] which, at the estimated distance of this system, yields a physical size of about 14 times the radius of the Sun.^[6] The star is radiating 92^[7] times the Sun's luminosity from its photosphere at an effective temperature of 5,183 K.^[5] Its companion, component B, is an A-type star about 0.9 magnitudes fainter than the primary.^[3]

References

^ ^a ^b ^c ^d ^e ^f 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.
^ ^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), 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, A61.
^ ^a ^b ^c ^d Ammler-von Eiff, M.; Reiners, A. (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: 31, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, A116.
^ ^a ^b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(130\cdot 1.00\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 28\cdot R_{\bigodot }\end{aligned}}$
^ ^a ^b 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.{{citation}}: CS1 maint: unflagged free DOI (link)
^ "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.{{citation}}: CS1 maint: unflagged free DOI (link)
^ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.

[vanLeeuwen2007-1] ^ ^a ^b ^c ^d ^e ^f 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.

[Johnson1966-2] Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J.

[Parsons1998-3] 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.

[deBruijne2012-4] 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, A61.

[AmmlerVonEiff2012-5] Ammler-von Eiff, M.; Reiners, A. (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: 31, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, A116.

[lang2006-6] Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(130\cdot 1.00\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 28\cdot R_{\bigodot }\end{aligned}}$

[McDonald2012-7] 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.{{citation}}: CS1 maint: unflagged free DOI (link)

[SIMBAD-8] "del Men". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-16.{{cite web}}: CS1 maint: postscript (link)

[Eggleton2008-9] 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.{{citation}}: CS1 maint: unflagged free DOI (link)

[Richichi2005-10] Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.

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Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Mensa
Right ascension	04^h 17^m 59.2718^s^[1]
Declination	−80° 12′ 50.511″^[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 (R_v)	−20.0±4.3^[4] km/s
Proper motion (μ)	RA: +27.53^[1] mas/yr Dec.: +61.56^[1] mas/yr
Parallax (π)	7.70 ± 0.27 mas^[1]
Distance	420 ± 10 ly (130 ± 5 pc)
Absolute magnitude (M_V)	0.34^[5]

Details
δ Men A
Radius	14^[6] `R`_☉
Luminosity	92^[7] `L`_☉
Temperature	5,183^[5] 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^[8]
Database references
SIMBAD	data