HD 11964is abinary starsystem located 110[1]light-yearsaway from theSunin theequatorialconstellationofCetus.It is visible in binoculars or a telescope but is too faint to be seen with the naked eye, having anapparent visual magnitudeof 7.51.[2]The system is drifting closer to the Sun with aradial velocityof −9 km/s.[5]Twoextrasolar planetshave been confirmed to orbit the primary.
Properties
editThe primary, component A, is aG-type main-sequence starwith astellar classificationof G9VCN+1.[3]The suffix notation indicates an overabundance of thecyano radicalin thespectrum.Houk and Swift (1999) found a class of G8IV, suggesting it is instead a moreevolvedsubgiant star.[10]It is around seven[6]billion years old and is spinning slowly with aprojected rotational velocityof 1.5 km/s.[5]The star has 1.1[6]times themass of the Sunand 2.2[7]times theSun's radius.It is radiating 2.9[6]times theluminosity of the Sunfrom itsphotosphereat aneffective temperatureof 5,321 K.[5]
A widebinarycompanion star was discovered in 2000.[11]This secondary, designated component B, has a visual magnitude of 11.11 and lies at anangular separationof29.7″along aposition angleof 134°, as of 2015.[12]It is ared dwarfwith 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
editIn 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. Gregoryclaimed that there was a third planet in the system on the basis ofBayesian analysisof the radial velocity data. The planet was claimed to have a mass similar to that ofSaturnand 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 theEarthin orbit around the Sun.[13]The planet was not detected in re-reduced data in an analysis published in theAstrophysical Journalin 2009.[14]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | ≥ 0.11MJ | 0.229 | 37.82 | 0.15 | — | — |
| b | ≥0.61±0.1MJ | 3.34±0.4 | 2,110±70 | 0.06±0.2 | — | — |
See also
editReferences
edit- ^abcdefghijBrown, A. G. A.;et al. (Gaia collaboration) (August 2018)."GaiaData 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:
- ^abcdefghijAnderson, 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.S2CID119257644.
- ^abGray, 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.S2CID119476992.
- ^abAlonso-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.S2CID53135130.[permanent dead link]
- ^abcdefghJofré, 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.S2CID53666931.
- ^abcdefGhezzi, 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,S2CID119206634
- ^abvan 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.S2CID18370219.
- ^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.S2CID118481247.52.
- ^"HD 11964".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2019-11-12.
- ^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 fromthe originalon 2011-07-25.Retrieved2008-10-07.
- ^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.Retrieved2015-07-22.
- ^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.S2CID16796923.
- ^abWright, 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.S2CID18169921.
External links
edit- Extrasolar Planet InteractionsArchived2016-05-05 at theWayback Machineby Rory Barnes & Richard Greenberg, Lunar and Planetary Lab, University of Arizona