Astronomy:HD 30479
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Mensa |
| Right ascension | 04h 38m 21.7254s[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 (Rv) | 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[1] mas |
| Distance | 540 ± 2 ly (165.6 ± 0.6 pc) |
| Absolute magnitude (MV) | −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 | |
| Database references | |
| SIMBAD | data |
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]
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.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 2.0 2.1 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode: 2000A&A...355L..27H.
- ↑ 3.0 3.1 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.
- ↑ 4.0 4.1 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.
- ↑ 5.0 5.1 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. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 6.0 6.1 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. doi:10.1051/0004-6361/201935765. ISSN 0004-6361. Bibcode: 2019A&A...628A..94A.
- ↑ 7.0 7.1 Lang, Kenneth R. (2006). Astrophysical formulae. Astronomy and astrophysics library. 1 (3 ed.). Birkhäuser. ISBN 3-540-29692-1. https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41.. The radius (R*) is given by:
- [math]\displaystyle{ \begin{align} 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{align} }[/math]
- ↑ 8.0 8.1 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. doi:10.1093/mnras/stx1433. Bibcode: 2017MNRAS.471..770M.
- ↑ 9.0 9.1 9.2 9.3 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. 7734. pp. 77344E. doi:10.1117/12.857024. Bibcode: 2010SPIE.7734E..4EL.
- ↑ 10.0 10.1 10.2 Eggen, O. J. (February 1994). "Evolved GK stars near the Sun. 2: The young disk population". The Astronomical Journal 107: 594. doi:10.1086/116879. ISSN 0004-6256. Bibcode: 1994AJ....107..594E.
- ↑ 11.0 11.1 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. doi:10.1051/0004-6361/201220762. ISSN 0004-6361. Bibcode: 2014A&A...561A.126D.
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