HD 126209

HD 126209

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Apus
Right ascension	14^h 29^m 37.00634^s[1]
Declination	−76° 43′ 44.6977″[1]
Apparent magnitude (V)	6.06±0.01[2]
Characteristics
Spectral type	K0/1 III[3]
U−B color index	+1.11[4]
B−V color index	+1.18[4]
Astrometry
Radial velocity (Rv)	−8.1±3.7[5] km/s
Proper motion (μ)	RA: −27.950 mas/yr[1] Dec.: −27.585 mas/yr[1]
Parallax (π)	5.8482 ± 0.1281 mas[1]
Distance	560 ± 10 ly (171 ± 4 pc)
Absolute magnitude (MV)	+0.18[6]
Details
Mass	1.22[7] M☉
Radius	16.83[8] R☉
Luminosity	196^+10 −7[1] L☉
Surface gravity (log g)	1.78[7] cgs
Temperature	4,622±122[9] K
Metallicity [Fe/H]	−0.30[10] dex
Rotational velocity (v sin i)	<1[11] km/s
Other designations
11 G. Apodis[12], CPD−76°826, HD 126209, HIP 70874, HR 5389, SAO 257163[13]
Database references
SIMBAD	data

HD 126209, also known as HR 5389, is a solitary, orange hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.06,[2] making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be 560 light years distant. It appears to be approaching the Solar System with a fairly constrained heliocentric radial velocity of −8.1 km/s.[5] De Mederios et al. (2014) found the radial velocity to be variable, making it a probable spectroscopic binary.[11] Eggen (1993) lists it as a member of the old disk population.[14]

This is an evolved red giant with a spectral classification of K0/1 III.[3] This indicates that it has the spectrum intermediate of a K0 and K1 giant. It has 1.22 times the mass of the Sun[7] and due to its evolved state, expanded to 16.8 times its girth.[8] It radiates 196 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 4,622 K.[9] HD 126209 is said to be metal deficient, having an iron abundance only half of the Sun's.[10] Like most giant stars, it spins slowly, having a projected rotational velocity lower than 1 km/s.[11]

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 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°. 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. Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
6. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
7. Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. eISSN 1432-0746. ISSN 0004-6361.
8. Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (20 December 2021). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv:2109.10912. Bibcode:2022A&A...657A...7K. doi:10.1051/0004-6361/202142146. eISSN 1432-0746. ISSN 0004-6361.
9. Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
10. Charbonnel, C.; Lagarde, N.; Jasniewicz, G.; North, P. L.; Shetrone, M.; Krugler Hollek, J.; Smith, V. V.; Smiljanic, R.; Palacios, A.; Ottoni, G. (January 2020). "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era". Astronomy & Astrophysics. 633: A34. arXiv:1910.12732. Bibcode:2020A&A...633A..34C. doi:10.1051/0004-6361/201936360. eISSN 1432-0746. ISSN 0004-6361.
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". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. eISSN 1432-0746. ISSN 0004-6361.
12. Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
13. "HD 126209". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved November 6, 2022.
14. Eggen, O. J. (July 1993). "Evolved GK stars near the sun. I - The old disk population". The Astronomical Journal. 106: 80. Bibcode:1993AJ....106...80E. doi:10.1086/116622.