HD 30479

HD 30479 (HR 1531) is a solitary star in the southern circumpolar constellation Mensa. It has an apparent magnitude of 6.04,^[2] making it barely visible to the naked eye even under ideal conditions. It is located at a distance of 540 light years^[1] but is receding with a heliocentric radial velocity of 10.3 km/s.^[5]

ConstellationMensa

Right ascension04^h 38^m 21.7254^s^[1]

Declination−77° 39′ 21.6185″^[1]

Apparentmagnitude(V)6.04 ± 0.01^[2]

Quick facts Observation data Epoch J2000 Equinox J2000, Constellation ...

HD 30479
Observation data Epoch J2000 Equinox J2000
Constellation	Mensa
Right ascension	04^h 38^m 21.7254^s^[1]
Declination	−77° 39′ 21.6185″^[1]
Apparent magnitude (V)	6.04 ± 0.01^[2]
Characteristics
Spectral type	K2 III^[3]
U−B color index	+0.95^[4]
B−V color index	+1.10^[4]
Astrometry
Radial velocity (R_v)	10.3 ± 0.1^[5] km/s
Proper motion (μ)	RA: −6.975^[1] mas/yr Dec.: −11.166^[1] mas/yr
Parallax (π)	6.0377±0.0223 mas^[1]
Distance	540 ± 2 ly (165.6 ± 0.6 pc)
Absolute magnitude (M_V)	−0.05
Details
Mass	1.28^[6] `M`_☉
Radius	17.99^[7] R_☉
Luminosity	116^[8] `L`_☉
Surface gravity (log g)	2^[9] cgs
Temperature	4,390^[9] K
Metallicity [Fe/H]	−0.15^[10] dex
Rotational velocity (v sin i)	<1^[11] km/s
Other designations
13 G. Mensae, CPD−77°181, FK5 2350, GC 5750, HD 30479, HIP 21611, HR 1531, SAO 256116
Database references
SIMBAD	data

HD 30479 has a stellar classification of K2 III,^[3] indicating that it is an early K-type giant star and has an angular diameter of 1.01±0.07 mas^[9] (after limb darkening correction). This yields a radius 17.99^[7] times that of the Sun at its estimated distance. At present it has 1.28^[6] times the mass of the Sun and radiates at 116^[8] times the luminosity of the Sun at an effective temperature of 4,390^[9] K from its enlarged photosphere, which gives it an orange glow. HD 30479 is believed to be one of the metal-deficient members of the young disk population^[10] with an iron abundance of 71%^[10] that of the Sun. Currently, it spins leisurely with a projected rotational velocity less than 1 km/s,^[11] common for giants.

[1]
Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
[2]
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.
[3]
Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0. Bibcode:1975mcts.book.....H.
[4]
Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
[5]
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.
[6]
Anders, F.; et al. (1 August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. ISSN 0004-6361. S2CID 131780028.
[7]
Lang, Kenneth R. (2006). Astrophysical formulae. Astronomy and astrophysics library. Vol. 1 (3 ed.). Birkhäuser. ISBN 3-540-29692-1.. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(165.6\cdot 1.01\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 35.98\cdot R_{\bigodot }\end{aligned}}$
[8]
McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433.
[9]
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.
[10]
Eggen, O. J. (February 1994). "Evolved GK stars near the Sun. 2: The young disk population". The Astronomical Journal. 107: 594. Bibcode:1994AJ....107..594E. doi:10.1086/116879. ISSN 0004-6256.
[11]
De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (January 2014). "A catalog of rotational and radial velocities for evolved stars: V. Southern stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. ISSN 0004-6361.

References

Related Articles