HD 118889

HD 118889
Observation data; Epoch J2000 Equinox J2000
Constellation	Boötes
Right ascension	13h 39m 34.61613s
Declination	+10° 44′ 46.5827″
Apparent magnitude (V)	5.57 (6.35 + 6.47)‍
Characteristics
Evolutionary stage	Main sequence
Spectral type	F0V
U−B color index	+0.045
B−V color index	+0.33
Astrometry
Radial velocity (Rv)	−25.9±1.9 km/s
Proper motion (μ)	RA: −114.96 mas/yr ; Dec.: −11.74 mas/yr
Parallax (π)	16.67±0.58 mas
Distance	196 ± 7 ly ; (60 ± 2 pc)
Absolute magnitude (MV)	+2.40
Orbit
Period (P)	22.460±0.019 yr
Semi-major axis (a)	0.19983±0.00055″
Eccentricity (e)	0.5450±0.0022
Inclination (i)	43.50±0.40°
Longitude of the node (Ω)	34.58±0.52°
Periastron epoch (T)	B 1929.850±0.024
Argument of periastron (ω); (secondary)	359.93±0.79°
Details
A
Mass	1.59 M☉
B
Mass	1.55 M☉
Other designations
	BD+11°2589, HD 118889, HIP 66640, HR 5138, SAO 100654, ADS 8987, WDS 13396+1045, BU 612
Database references
SIMBAD	data

HD 118889 is a binary star system in the northern constellation of Boötes. It is faintly visible to the naked eye as a point of light with an apparent visual magnitude of 5.57.^[1] The system is located at a distance of approximately 196 light years from the Sun based on stellar parallax,^[2] but is drifting closer with a radial velocity of −26 km/s.^[8]

The binary components of this system were first measured by S. W. Burnham in 1878 and it was given the discovery code BU 612.^[12] The pair are orbiting each other with a period of 22.46 years with an eccentricity (ovalness) of 0.545. The primary component is magnitude 6.35, with the secondary slightly fainter at magnitude 6.47.^[3]

A third star, 3.5″ away, is a 12th-magnitude common-proper-motion companion. Any orbit would take over a thousand years.^[11]

References

^ ^a ^b ^c 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 ^c ^d ^e ^f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600
^ ^a ^b Malkov, O. Yu.; et al. (2012), "Dynamical Masses of a Selected Sample of Orbital Binaries", Astronomy & Astrophysics, 546: 5, Bibcode:2012A&A...546A..69M, doi:10.1051/0004-6361/201219774, A69
^ Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377^{[permanent dead link]}
^ Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789
^ Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298
^ ^a ^b Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M
^ ^a ^b Holmberg, J.; et al. (2007), "The Geneva-Copenhagen survey of the Solar neighbourhood. II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk", Astronomy & Astrophysics, 475 (2): 519–537, arXiv:0707.1891, Bibcode:2007A&A...475..519H, doi:10.1051/0004-6361:20077221, S2CID 119054949
^ Reiners, Ansgar (January 2006), "Rotation- and temperature-dependence of stellar latitudinal differential rotation", Astronomy and Astrophysics, 446 (1): 267–277, arXiv:astro-ph/0509399, Bibcode:2006A&A...446..267R, doi:10.1051/0004-6361:20053911, S2CID 8642707
^ "Sixth Catalog of Orbits of Visual Binary Stars", United States Naval Observatory, retrieved 2021-04-01
^ ^a ^b ^c Tokovinin, Andrei (2018), "The Updated Multiple Star Catalog", The Astrophysical Journal Supplement Series, 235 (1): 6, arXiv:1712.04750, Bibcode:2018ApJS..235....6T, doi:10.3847/1538-4365/aaa1a5
^ Mason, Brian D.; et al. (February 1999), "Binary Star Orbits from Speckle Interferometry. I. Improved Orbital Elements of 22 Visual Systems", The Astronomical Journal, 117 (2): 1023–1036, Bibcode:1999AJ....117.1023M, doi:10.1086/300748, S2CID 122382211

External links

[Anderson_Francis_2012-1] 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

[vanLeeuwen2007-2] ^ ^a ^b ^c ^d ^e ^f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600

[aa546_A69_5-3] Malkov, O. Yu.; et al. (2012), "Dynamical Masses of a Selected Sample of Orbital Binaries", Astronomy & Astrophysics, 546: 5, Bibcode:2012A&A...546A..69M, doi:10.1051/0004-6361/201219774, A69

[Schröder_et_al_2009-4] Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377^{[permanent dead link]}

[Zorec_Royer_2012-5] Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789

[aaa463_2_671-6] Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298

[MERMILLIOD-7] Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M

[aa475_519-8] Holmberg, J.; et al. (2007), "The Geneva-Copenhagen survey of the Solar neighbourhood. II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk", Astronomy & Astrophysics, 475 (2): 519–537, arXiv:0707.1891, Bibcode:2007A&A...475..519H, doi:10.1051/0004-6361:20077221, S2CID 119054949

[Reiners2006-9] Reiners, Ansgar (January 2006), "Rotation- and temperature-dependence of stellar latitudinal differential rotation", Astronomy and Astrophysics, 446 (1): 267–277, arXiv:astro-ph/0509399, Bibcode:2006A&A...446..267R, doi:10.1051/0004-6361:20053911, S2CID 8642707

[ORB6-10] "Sixth Catalog of Orbits of Visual Binary Stars", United States Naval Observatory, retrieved 2021-04-01

[msc-11] Tokovinin, Andrei (2018), "The Updated Multiple Star Catalog", The Astrophysical Journal Supplement Series, 235 (1): 6, arXiv:1712.04750, Bibcode:2018ApJS..235....6T, doi:10.3847/1538-4365/aaa1a5

[Mason1999-12] Mason, Brian D.; et al. (February 1999), "Binary Star Orbits from Speckle Interferometry. I. Improved Orbital Elements of 22 Visual Systems", The Astronomical Journal, 117 (2): 1023–1036, Bibcode:1999AJ....117.1023M, doi:10.1086/300748, S2CID 122382211

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HD 118889

References

External links

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