HD 120987

Last updated
HD 120987
Observation data
Epoch J2000        Equinox J2000
Constellation Centaurus
Right ascension 13h 53m 32.76039s [1]
Declination −35° 39 51.3200 [1]
Apparent magnitude  (V)5.565 [2]
(6.27 / 6.38) [3]
Characteristics
Spectral type F4V (F0V + F1V) [4]
U−B color index -0.03 [5]
B−V color index +0.44 [5]
Astrometry
Radial velocity (Rv)-8.00 ± 7.40 [6]  km/s
Proper motion (μ)RA: -83.39 [1]   mas/yr
Dec.: -25.36 [1]   mas/yr
Parallax (π)19.13 ± 0.93  mas [1]
Distance 170 ± 8  ly
(52 ± 3  pc)
Orbit [3]
Period (P)373.0 yr
Semi-major axis (a)1.519″
Eccentricity (e)0.775
Inclination (i)74.2°
Longitude of the node (Ω)112.3°
Periastron epoch (T)B 1958.57
Argument of periastron (ω)
(secondary)
90.7°
Details
HD 120987 A
Mass 1.56 [7]   M
HD 120987 B
Mass 1.53 [7]   M
Other designations
CD−35° 9090, HD  120987, HIP  67819, HR  5222, SAO  204955 [2]
Database references
SIMBAD data

HD 120987 (y Centauri or y Cen) is a star system located in the constellation Centaurus. HD 120987 is a quintuple star system located 50 pc (163 light years) from the Sun. The system has an apparent magnitude of 5.565. [2] Based on the system's parallax, it is located some 172 light-years (52 parsecs) away. [1]

HD 120987 appears to be a single F-type star with the spectral classification F4V, but closer inspection reveals it to be two similar F-type main-sequence stars with spectral classifications of F0V and F1V, respectively. [4] The two orbit each other every 373 years, and are separated by 1.519 arcseconds while taking a very eccentric orbit. [3]

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References

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  2. 1 2 3 "* y Cen". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 19 July 2017.
  3. 1 2 3 "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. Retrieved 19 July 2017.
  4. 1 2 Cvetkovic, Z.; Ninkovic, S. (2010). "On the Component Masses of Visual Binaries". Serbian Astronomical Journal. 180 (180): 71. Bibcode:2010SerAJ.180...71C. doi: 10.2298/SAJ1080071C .
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  6. Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv: 0705.0878 . Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID   119323941.
  7. 1 2 Tokovinin, Andrei (2014). "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs". The Astronomical Journal. 147 (4): 87. arXiv: 1401.6827 . Bibcode:2014AJ....147...87T. doi:10.1088/0004-6256/147/4/87. S2CID   56066740.