Binary star system in the constellation Hydra
HR 4458 is abinary starsystem in theequatorialconstellation ofHydra. It has theGould designation289 G. Hydrae;HR 4458 is theBright Star Catalogue designation. At a distance of 31.13 light years, it is the closest star system to theSolar System within this constellation. This object is visible to the naked eye as a dim, orange-hued star with anapparent visual magnitude of 5.97.[2] It is moving closer to the Earth with a heliocentricradial velocity of −22 km/s.[5]
The primary component isK-type main-sequence star with astellar classification of K0 V.[3] It is around five[11] billion years old with 84%[7] of theSun's radius. The star is radiating 37%[8] of theSun's luminosity from itsphotosphere at aneffective temperature of 5,241 K.[9] It has been examined for the presence of aninfrared excess, but none was detected.[8]
There is acommon proper motion companion at anangular separation of 16.2″,[4] corresponding to aprojected separation of162.5 AU.[13] This is awhite dwarf star with a classification of DC8.[4] The orbital period of the pair is estimated as 1,110 years.[13]
- ^abcdeBrown, 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 atVizieR.
- ^abcdMermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)".Catalogue of Eggen's UBV Data.Bibcode:1986EgUBV........0M.
- ^abGray, R. O.; et al. (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):161–70.arXiv:astro-ph/0603770.Bibcode:2006AJ....132..161G.doi:10.1086/504637.S2CID 119476992.
- ^abcHolberg, J. B.; et al. (November 2013)."Where are all the Sirius-like binary systems?".Monthly Notices of the Royal Astronomical Society.435 (3):2077–2091.arXiv:1307.8047.Bibcode:2013MNRAS.435.2077H.doi:10.1093/mnras/stt1433.
- ^abNidever, David L.; et al. (August 2002). "Radial Velocities for 889 Late-Type Stars".The Astrophysical Journal Supplement Series.141 (2):503–522.arXiv:astro-ph/0112477.Bibcode:2002ApJS..141..503N.doi:10.1086/340570.S2CID 51814894.
- ^Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics",Astronomy and Astrophysics,501 (3):941–947,arXiv:0811.3982,Bibcode:2009A&A...501..941H,doi:10.1051/0004-6361/200811191,S2CID 118577511.
- ^abJohnson, H. M.; Wright, C. D. (183)."Predicted infrared brightness of stars within 25 parsecs of the sun".Astrophysical Journal Supplement Series.53 (2):643–711.Bibcode:1983ApJS...53..643J.doi:10.1086/190905.
- ^abcEiroa, C.; et al. (July 2013). "DUst around NEarby Stars. The survey observational results".Astronomy & Astrophysics.555: A11.arXiv:1305.0155.Bibcode:2013A&A...555A..11E.doi:10.1051/0004-6361/201321050.S2CID 377244.
- ^abcdRamírez, I.; et al. (September 2012). "Lithium Abundances in nearby FGK Dwarf and Subgiant Stars: Internal Destruction, Galactic Chemical Evolution, and Exoplanets".The Astrophysical Journal.756 (1): 46.arXiv:1207.0499.Bibcode:2012ApJ...756...46R.doi:10.1088/0004-637X/756/1/46.S2CID 119199829.
- ^Martínez-Arnáiz, R.; et al. (September 2010)."Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter"(PDF).Astronomy and Astrophysics.520: A79.arXiv:1002.4391.Bibcode:2010A&A...520A..79M.doi:10.1051/0004-6361/200913725.S2CID 43455849. Archived fromthe original(PDF) on 2017-09-22. Retrieved2018-11-04.
- ^abMamajek, Eric E.; Hillenbrand, Lynne A. (November 2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics".The Astrophysical Journal.687 (2):1264–1293.arXiv:0807.1686.Bibcode:2008ApJ...687.1264M.doi:10.1086/591785.S2CID 27151456.
- ^"HD 100623".SIMBAD.Centre de données astronomiques de Strasbourg. RetrievedMay 6, 2019.
- ^abRodriguez, David R.; et al. (2015)."Stellar multiplicity and debris discs: An unbiased sample".Monthly Notices of the Royal Astronomical Society.449 (3): 3160.arXiv:1503.01320.Bibcode:2015MNRAS.449.3160R.doi:10.1093/mnras/stv483.
