HD 210056, also known as HR 8432, is a solitary orange hued star located in the southern circumpolar constellation Octans. Eggen (1993) listed it as a member of the old disk population.[12]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Octans |
| Right ascension | 22h 11m 54.98416s[1] |
| Declination | −76° 06′ 57.6788″[1] |
| Apparent magnitude (V) | 6.13±0.01[2] |
| Characteristics | |
| Spectral type | K0 III[3] |
| U−B color index | +0.82[4] |
| B−V color index | +1.00[4] |
| Astrometry | |
| Radial velocity (Rv) | 24±1[5] km/s |
| Proper motion (μ) | RA: −59.351 mas/yr[1] Dec.: −40.005 mas/yr[1] |
| Parallax (π) | 11.1656 ± 0.0205 mas |
| Distance | 292.1 ± 0.5 ly (89.6 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.41[6] |
| Details[7] | |
| Mass | 1.59±0.07 M☉ |
| Radius | 7.72±0.13 R☉ |
| Luminosity | 29.7±0.5 L☉ |
| Surface gravity (log g) | 2.86±0.10 cgs |
| Temperature | 4,849±37 K |
| Metallicity [Fe/H] | −0.08±0.03 dex |
| Rotational velocity (v sin i) | <1.5[8] km/s |
| Age | 2.10±0.22[9] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The object has an apparent magnitude of 6.13,[2] making it barely visible to the naked eye. Based on parallax measurements from the Gaia satellite, the object is estimated to be 292 light years distant.[1] It appears to be receding with a heliocentric radial velocity of 24 km/s.[5] At its current distance, HD 210056's brightness is diminished by 0.2 magnitudes due to interstellar dust. It has an absolute magnitude of +1.41.[13]
This is an evolved giant star with a stellar classification of K0 III. It has 1.59 times the mass of the Sun but has expanded to 7.72 times its girth.[7] It radiates 29.7 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,849 K.[7] Based on asteroseismologic measurements, HD 210056 is estimated to be 2 billion years old.[9] The star has about 90% of the Sun's metallicity — what astronomers define a star's abundance of chemical elements heavier than helium.[7] It currently spins slowly with a projected rotational velocity lower than 1.5 km/s.[9]
References
edit- ^ 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.
- ^ a b 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.
- ^ 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.
- ^ 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 Ottoni, G.; Udry, S.; Ségransan, D.; Buldgen, G.; Lovis, C.; Eggenberger, P.; Pezzotti, C.; Adibekyan, V.; Marmier, M.; Mayor, M.; Santos, N. C.; Sousa, S. G.; Lagarde, N.; Charbonnel, C. (January 2022). "CORALIE radial-velocity search for companions around evolved stars (CASCADES): I. Sample definition and first results: Three new planets orbiting giant stars". Astronomy & Astrophysics. 657: A87. arXiv:2201.01528. Bibcode:2022A&A...657A..87O. doi:10.1051/0004-6361/202040078. eISSN 1432-0746. ISSN 0004-6361.
- ^ 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.
- ^ a b c Aguirre, Víctor Silva; et al. (29 January 2020). "Detection and Characterization of Oscillating Red Giants: First Results from the TESS Satellite". The Astrophysical Journal. 889 (2): L34. arXiv:1912.07604. Bibcode:2020ApJ...889L..34S. doi:10.3847/2041-8213/ab6443. eISSN 2041-8213.
- ^ 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.
- ^ "HD 210056". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved November 21, 2022.
- ^ 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.
- ^ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711.