HD 164712, also known as HR 6731 is an orange hued star located in the southern constellation of Apus. It has an apparent magnitude of 5.86,[2] making it faintly visible to the naked eye if viewed under ideal conditions. Parallax measurements place the object at a distance of 229 light-years (70 pc),[1] and it is currently receding with a heliocentric radial velocity of 14.8 km/s.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Apus |
| Right ascension | 18h 11m 15.80732s[1] |
| Declination | −75° 53′ 29.4836″[1] |
| Apparent magnitude (V) | 5.86[2] |
| Characteristics | |
| Evolutionary stage | red giant branch[3] |
| Spectral type | K2 III[4] |
| U−B color index | +1.43[5] |
| B−V color index | +1.24[5] |
| Astrometry | |
| Radial velocity (Rv) | 14.8±3.2[6] km/s |
| Proper motion (μ) | RA: +16.16 mas/yr[1] Dec.: -296.819 mas/yr[1] |
| Parallax (π) | 14.2681 ± 0.0440 mas[1] |
| Distance | 228.6 ± 0.7 ly (70.1 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.48[2] |
| Details | |
| Mass | 1.15[7] M☉ |
| Radius | 9.09[8] R☉ |
| Luminosity | 33.1+1.6 −1.5[9] L☉ |
| Surface gravity (log g) | 2.55[7] cgs |
| Temperature | 4,360±90[9] K |
| Metallicity [Fe/H] | +0.24[10] dex |
| Rotational velocity (v sin i) | <1.5[11] km/s |
| Age | 4.54+0.46 −0.56[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 164712 has a stellar classification of K2 III, indicating that it is a red giant. David Stanley Evans gave it a slightly cooler class of K3 III.[14] Gaia Data Release 3 models place it on the bump of red giant branch, a period of temporary contraction.[3] At present it has 1.15 times the mass of the Sun[7] but at an age of 4.54 billion years,[3] it has expanded to 9.09 times its girth.[8] It shines with a luminosity of 33.1 L☉ from its enlarged photosphere at an effective temperature of 4,360 K.[9] HD 164712 is a thick disk star with an iron abundance 73% above solar level.[10] This makes it metal enriched. Like most giants, it spins slowly, with its projected rotational velocity being lower than 1.5 km/s.[11]
HR 6731 has two faint companions. Component B is a 13th magnitude object separated 24.6″ away along a position angle of 299°.[15] Component C is a 14th magnitude star 18.1″ away along a position angle of 109°.[15] The first one is a background object while the other one appears to be physically related.[15] As for HD 164712, it shows indications of an infrared excess, suggesting there may be a dusty disk in orbit around the star.[16][17]
References
edit- ^ a b c d e 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.
- ^ a b c 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.
- ^ a b c d 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.
- ^ 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.
- ^ a b 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.
- ^ a b 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.
- ^ a b c 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.
- ^ a b 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.
- ^ a b c 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.
- ^ a b 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.
- ^ a b 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.
- ^ 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.
- ^ "HR 6731". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved August 15, 2022.
- ^ Evans, D. S. (1966). "Fundamental data for Southern stars (6th list)". Royal Greenwich Observatory Bulletins. 110: 185. Bibcode:1966RGOB..110..185E.
- ^ a b c Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.
- ^ Zuckerman, B.; Kim, Sungsoo S.; Liu, T. (June 1995). "Luminosity Class III Stars with Excess Far-Infrared Emission". The Astrophysical Journal. 446: L79. Bibcode:1995ApJ...446L..79Z. doi:10.1086/187935. eISSN 1538-4357. ISSN 0004-637X.
- ^ Plets, H.; et al. (July 1997), "Giants with infrared excess.", Astronomy and Astrophysics, 323: 513–523, Bibcode:1997A&A...323..513P