| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Octans |
| Right ascension | 23h 44m 40.8646s[1] |
| Declination | −78° 47′ 29.1861″[1] |
| Apparent magnitude (V) | 5.74±0.01[2] |
| Characteristics | |
| Spectral type | K1 III[3] |
| U−B color index | +1.06[4] |
| B−V color index | +1.11[4] |
| Astrometry | |
| Radial velocity (Rv) | 21.3±0.8[5] km/s |
| Proper motion (μ) | RA: +49.327 mas/yr[1] Dec.: +7.345 mas/yr[1] |
| Parallax (π) | 5.7766 ± 0.0592 mas[1] |
| Distance | 565 ± 6 ly (173 ± 2 pc) |
| Absolute magnitude (MV) | −0.11[6] |
| Details | |
| Mass | 1.26[7] M☉ |
| Radius | 18.77[8] R☉ |
| Luminosity | 151±2[9] L☉ |
| Surface gravity (log g) | 1.95[7] cgs |
| Temperature | 4,865±122[10] K |
| Metallicity [Fe/H] | +0.37[11] dex |
| Rotational velocity (v sin i) | <1[12] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 222806 (HR 8995) is a suspected astrometric binary[15] in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.74,[2] allowing it to be faintly seen with the naked eye. Parallax measurements place the system at a distance of 565 light years[1] and it is currently receding with a heliocentric radial velocity of 21 km/s.[5]
The visible component has a stellar classification of K1 III,[3] indicating that it is a red giant. At present it has 126% the mass of the Sun,[7] but has expanded to almost 19 times its girth.[8] It radiates at 151 times the luminosity of the Sun[9] from its enlarged photosphere at an effective temperature of 4,865 K,[10] giving it an orange hue. HD 222806 is metal enriched with an iron abundance over twice that of the Sun and is believed to be a member of the young disk population.[11] It spins with a projected rotational velocity lower than 1 km/s.[12]
References
- ^ 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 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.
- ^ a b 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.
- ^ 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. 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. ISSN 1063-7737. S2CID 255204555.
- ^ 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. ISSN 0004-6361.
- ^ a b Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "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.
- ^ a b 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.
- ^ 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. ISSN 0004-6256.
- ^ a b 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.
- ^ 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: V. Southern stars⋆⋆⋆". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. ISSN 0004-6361.
- ^ "HD 222806". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 June 2022.
- ^ 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.
- ^ Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. eISSN 1365-2966. ISSN 0035-8711.
This page was last edited on 17 January 2024, at 02:00