HD 11964 is a binary star system located 110 [1] light-years away from the Sun in the equatorial constellation of Cetus. It is visible in binoculars or a telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 7.51. [2] The system is drifting closer to the Sun with a radial velocity of −9 km/s. [5] Two extrasolar planets have been confirmed to orbit the primary.
Properties
The primary, component A, is a G-type main-sequence star with a stellar classification of G9VCN+1. [3] The suffix notation indicates an overabundance of the cyano radical in the spectrum. Houk and Swift (1999) found a class of G8IV, suggesting it is instead a more evolved subgiant star. [10] It is around seven [6] billion years old and is spinning slowly with a projected rotational velocity of 1.5 km/s. [5] The star has 1.1 [6] times the mass of the Sun and 2.2 [7] times the Sun's radius. It is radiating 2.9 [6] times the luminosity of the Sun from its photosphere at an effective temperature of 5,321 K. [5]
A wide binary companion star was discovered in 2000. [11] This secondary, designated component B, has a visual magnitude of 11.11 and lies at an angular separation of 29.7 ″ along a position angle of 134°, as of 2015. [12] It is a red dwarf with a class of M0V, [4] and has just 0.6 times the Sun's radius. It is radiating 0.085 times the Sun's luminosity at an effective temperature of 4,033 K. [1]
Planetary system
In August 2005, two planets were discovered orbiting the star, the innermost like Neptune and another like Jupiter orbiting at 3.34 AU. However, the second planet ( HD 11964 b) was not confirmed until May 2007. In September 2007, P.C. Gregory claimed that there was a third planet in the system on the basis of Bayesian analysis of the radial velocity data. The planet was claimed to have a mass similar to that of Saturn and located in a 360-day orbit. Gregory cautioned that the close match between the period of this planet to being exactly a year meant that the radial velocity variations may have been caused by insufficient correction for the motion of the Earth in orbit around the Sun. [13] The planet was not detected in re-reduced data in an analysis published in the Astrophysical Journal in 2009. [14]
| Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | ≥ 0.11 MJ | 0.229 | 37.82 | 0.15 | — | — |
| b | ≥ 0.61±0.1 MJ | 3.34±0.4 | 2,110±70 | 0.06±0.2 | — | — |
See also
References
- ^ a b c d e f g h i j 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 records at VizieR:
- ^ a b c d e f g h i j Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971. Bibcode: 2012AstL...38..331A. doi: 10.1134/S1063773712050015. S2CID 119257644.
- ^ a b Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv: astro-ph/0603770. Bibcode: 2006AJ....132..161G. doi: 10.1086/504637. S2CID 119476992.
- ^ a b Alonso-Floriano, F. J.; Morales, J. C.; Caballero, J. A.; Montes, D.; Klutsch, A.; Mundt, R.; Cortés-Contreras, M.; Ribas, I.; Reiners, Ansgar; Amado, P. J.; Quirrenbach, A.; Jeffers, S. V. (2015). "CARMENES input catalogue of M dwarfs" (PDF). Astronomy & Astrophysics. 577: A128. arXiv: 1502.07580. Bibcode: 2015A&A...577A.128A. doi: 10.1051/0004-6361/201525803. S2CID 53135130.[ permanent dead link]
- ^ a b c d e f g h Jofré, E.; et al. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics. 574: A50. arXiv: 1410.6422. Bibcode: 2015A&A...574A..50J. doi: 10.1051/0004-6361/201424474. S2CID 53666931.
- ^ a b c d e f Ghezzi, L.; et al. (December 2010), "Metallicities of Planet-hosting Stars: A Sample of Giants and Subgiants", The Astrophysical Journal, 725 (1): 721–733, arXiv: 1008.3539, Bibcode: 2010ApJ...725..721G, doi: 10.1088/0004-637X/725/1/721, S2CID 119206634
- ^ a b van Belle, Gerard T.; von Braun, Kaspar (2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal. 694 (2): 1085–1098. arXiv: 0901.1206. Bibcode: 2009ApJ...694.1085V. doi: 10.1088/0004-637X/694/2/1085. S2CID 18370219.
- ^ Mann, Andrew W.; et al. (February 2013). "Prospecting in Late-type Dwarfs: A Calibration of Infrared and Visible Spectroscopic Metallicities of Late K and M Dwarfs Spanning 1.5 dex". The Astronomical Journal. 145 (2): 15. arXiv: 1211.4630. Bibcode: 2013AJ....145...52M. doi: 10.1088/0004-6256/145/2/52. S2CID 118481247. 52.
- ^ "HD 11964". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-12.
- ^ Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode: 1999MSS...C05....0H.
- ^ Allen, C.; et al. (2000). "Wide binaries among high-velocity and metal-poor stars". Astronomy and Astrophysics. 356 (2): 529–540. Bibcode: 2000A&A...356..529A. Archived from the original on 2011-07-25. Retrieved 2008-10-07.
- ^ Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode: 2001AJ....122.3466M. doi: 10.1086/323920. Retrieved 2015-07-22.
- ^ Gregory, P. C. (2007). "A Bayesian periodogram finds evidence for three planets in HD 11964". Monthly Notices of the Royal Astronomical Society. 381 (4): 1607–1616. arXiv: 0709.0970. Bibcode: 2007MNRAS.381.1607G. doi: 10.1111/j.1365-2966.2007.12361.x. S2CID 16796923.
- ^ a b Wright, J. T.; et al. (2009). "Ten New and Updated Multi-planet Systems, and a Survey of Exoplanetary Systems". The Astrophysical Journal. 693 (2): 1084–1099. arXiv: 0812.1582. Bibcode: 2009ApJ...693.1084W. doi: 10.1088/0004-637X/693/2/1084. S2CID 18169921.
External links
- Extrasolar Planet Interactions by Rory Barnes & Richard Greenberg, Lunar and Planetary Lab, University of Arizona
