HD 120987

Last updated
HD 120987
Observation data
Epoch J2000        Equinox J2000
Constellation Centaurus [1]
Right ascension 13h 53m 32.76039s [2]
Declination −35° 39′ 51.3200″ [2]
Apparent magnitude  (V)5.565 [3] (6.27 / 6.38)‍ [4]
Characteristics
Spectral type F4V (F0V + F1V) [5]
U−B color index −0.03 [6]
B−V color index +0.44 [6]
Astrometry
Radial velocity (Rv)−8.00±7.40 [7] km/s
Proper motion (μ)RA: −83.39 [2] mas/yr
Dec.: −25.36 [2] mas/yr
Parallax (π)19.13±0.93  mas [2]
Distance 170 ± 8  ly
(52 ± 3  pc)
Absolute magnitude  (MV)+1.84 [1]
Orbit [4]
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 [8]   M☉
HD 120987 B
Mass 1.53 [8]   M☉
Other designations
CD−35°9090, HD 120987, HIP 67819, HR 5222, SAO 204955 [3]
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. [3] Based on the system's parallax, it is located some 172 light-years (52 parsecs) away. [2]

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. [5] The two orbit each other every 373 years, and are separated by 1.519 arcseconds while taking a very eccentric orbit. [4]

References

  1. 1 2 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.
  2. 1 2 3 4 5 6 van Leeuwen, F.; et al. (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.
  3. 1 2 3 "* y Cen". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 19 July 2017.
  4. 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.
  5. 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 .
  6. 1 2 Cousins, A. W. J.; Lagerweij, H. C. (1970). "Comparison Stars for Long Period Variables and RY Sagittarii". Monthly Notes of the Astron. Soc. Southern Africa. 29 (7). Bibcode:1970MNSSA..29....7C.
  7. ↑ 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.
  8. 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.


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