Visual binary star system in the constellation of Lupus
This article is about d Lupi and is not to be confused with
δ Lupi.
KT Lupi is a visualbinary star[5] system in theconstellationLupus. It is visible to the naked eye with a combinedapparent visual magnitude of 4.55.[3] As of 1983, the pair had anangular separation of2.19″±0.03″.[10] Based upon an annualparallax shift of7.6 mas[2] as seen from Earth's orbit, it is located 430 light-years from theSun. The system is moving further from the Earth with a heliocentricradial velocity of +6.5 km/s.[7] It is a member of the Upper Centaurus-Lupus sub-group of theScorpius–Centaurus association.[5]
The primary, component A, is avariableBe star,[6] with the variation being modulated by rotation.[13] It is visual magnitude 4.66[4] with astellar classification of B3 V,[5] matching aB-type main-sequence star. Hiltner et al. (1969) gave a class of B3 IVp,[14] which is still used in some studies.[8][9][10] It is a helium-weakchemically peculiar star showing an enhancedsilicon patch near the equator and a silicon-weak region close to the pole.[10] The star is about 21 million years old with nearly six[8] times themass of the Sun and three times theSun's radius.[9] It is radiating roughly 794[10] times theSun's luminosity from itsphotosphere at aneffective temperature of18,400 K.[9]
The secondary companion, component B, is of magnitude 6.62[4] with a class of B6 V.[5] It has 2.79 times theSun's mass.[11]
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- ^abcdAnderson, 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.
- ^abcEggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems",Monthly Notices of the Royal Astronomical Society,389 (2): 869,arXiv:0806.2878,Bibcode:2008MNRAS.389..869E,doi:10.1111/j.1365-2966.2008.13596.x,S2CID 14878976.
- ^abcdeChen, Christine H.; et al. (September 2012), "A Spitzer MIPS Study of 2.5-2.0 M⊙ Stars in Scorpius–Centaurus",The Astrophysical Journal,756 (2): 24,arXiv:1207.3415,Bibcode:2012ApJ...756..133C,doi:10.1088/0004-637X/756/2/133,S2CID 119278056, 133.
- ^abSamus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017), "General catalogue of variable stars: Version GCVS 5.1",Astronomy Reports,61 (1): 80,Bibcode:2017ARep...61...80S,doi:10.1134/S1063772917010085,S2CID 125853869.
- ^abde Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project",Astronomy & Astrophysics,546: 14,arXiv:1208.3048,Bibcode:2012A&A...546A..61D,doi:10.1051/0004-6361/201219219,S2CID 59451347, A61.
- ^abcdTetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun",Monthly Notices of the Royal Astronomical Society,410 (1):190–200,arXiv:1007.4883,Bibcode:2011MNRAS.410..190T,doi:10.1111/j.1365-2966.2010.17434.x,S2CID 118629873.
- ^abcdefgArcos, C.; et al. (March 2018), "Stellar parameters and H α line profile variability of Be stars in the BeSOS survey",Monthly Notices of the Royal Astronomical Society,474 (4):5287–5299,arXiv:1711.08675,Bibcode:2018MNRAS.474.5287A,doi:10.1093/mnras/stx3075,S2CID 74872624.
- ^abcdeBriquet, M.; et al. (January 2007), "Discovery of magnetic fields in three He variable Bp stars with He and Si spots",Astronomische Nachrichten,328 (1):41–45,arXiv:astro-ph/0610537,Bibcode:2007AN....328...41B,doi:10.1002/asna.200610702,S2CID 18724568.
- ^abKouwenhoven, M. B. N.; et al. (October 2007), "The primordial binary population. II. Recovering the binary population for intermediate mass stars in Scorpius OB2",Astronomy and Astrophysics,474 (1):77–104,arXiv:0707.2746,Bibcode:2007A&A...474...77K,doi:10.1051/0004-6361:20077719,S2CID 15750945.
- ^"KT Lup".SIMBAD.Centre de données astronomiques de Strasbourg. Retrieved3 September 2018.
- ^Briquet, M.; et al. (January 2004), "He and Si surface inhomogeneities of four Bp variable stars",Astronomy and Astrophysics,413:273–283,Bibcode:2004A&A...413..273B,doi:10.1051/0004-6361:20031450
- ^Hiltner, W. A.; et al. (July 1969), "MK Spectral Types for Bright Southern OB Stars",Astrophysical Journal,157: 313,Bibcode:1969ApJ...157..313H,doi:10.1086/150069
