Astronomy:Xi Cancri

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Short description: Spectroscopic binary star system in the constellation Cancer
Xi Cancri
Observation data
Equinox J2000.0]] (ICRS)
Constellation Cancer
Right ascension  09h 09m 21.53325s[1]
Declination +22° 02′ 43.6053″[1]
Apparent magnitude (V) +5.15[2] (5.70 + 6.20)[3]
Characteristics
Spectral type G9 III Fe-1 CH-0.5[4]
U−B color index +0.75[2]
B−V color index +0.96[2]
Astrometry
Radial velocity (Rv)+7.7±0.3[5] km/s
Proper motion (μ) RA: −1.00[1] mas/yr
Dec.: −0.52[1] mas/yr
Parallax (π)8.74 ± 0.49[1] mas
Distance370 ± 20 ly
(114 ± 6 pc)
Absolute magnitude (MV)−0.12[4]
Orbit[6][7]
Period (P)1,700.76 d
Semi-major axis (a)0.0105±0.0017[3]
Eccentricity (e)0.06
Periastron epoch (T)2,428,876.86 ± 10.0 JD
Argument of periastron (ω)
(secondary)
301.1°
Semi-amplitude (K1)
(primary)
4.4 km/s
Details
Luminosity118[8] L
Temperature5,101[8] K
Other designations
Nahn, ξ Cnc, 77 Cancri, BD+22° 2061, FK5 1239, HD 78515, HIP 44946, HR 3627, SAO 80666[9]
Database references
SIMBADdata

Xi Cancri (ξ Cancri, abbreviated Xi Cnc, ξ Cnc) is a spectroscopic binary star system in the zodiac constellation of Cancer. It is visible to the naked eye with an apparent visual magnitude of +5.15.[2] Based upon parallax measurements obtained during the Hipparcos mission,[1] it is roughly 370 light-years distant from the Sun.

The two components are designated Xi Cancri A (formally named Nahn /ˈnɑːn/)[10] and B.

Nomenclature

ξ Cancri (Latinised to Xi Cancri) is the system's Bayer designation. The designations of the two components as Xi Cancri A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[11]

Xi Cancri together with Lambda Leonis (Alterf) were the Persian Nahn, "the Nose", and the Coptic Piautos, "the Eye", both lunar asterisms.[12] Nahn was also the name given to Xi Cancri in a 1971 NASA technical memorandum.[13] In 2016, the IAU organized a Working Group on Star Names (WGSN)[14] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[15] It approved the name Nahn for the component Xi Cancri A on 1 June 2018 and it is now so included in the List of IAU-approved Star Names.[10]

Properties

At its present distance, the visual magnitude is diminished by an extinction factor of 0.135 due to interstellar dust.[3]

Xi Cancri is a single-lined spectroscopic binary star system with an orbital period of 4.66 years, an eccentricity of 0.06, and a semimajor axis of 0.01 arcsecond. The primary, Xi Cancri A, is a yellow G-type giant with an apparent magnitude of +5.70. Its companion, Xi Cancri B, is of magnitude 6.20.[3]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 Sturch, C. R.; Helfer, H. L. (November 1972), "UBVRI photometry of north galactic pole K giants. II", Astronomical Journal 77: 726, doi:10.1086/111344, Bibcode1972AJ.....77..726S. 
  3. 3.0 3.1 3.2 3.3 Malkov, O. Yu. et al. (2012), "Dynamical masses of a selected sample of orbital binaries", Astronomy & Astrophysics 546: A69, doi:10.1051/0004-6361/201219774, Bibcode2012A&A...546A..69M. 
  4. 4.0 4.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  5. de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  6. Pourbaix, D. et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics 424 (2): 727–732, doi:10.1051/0004-6361:20041213, Bibcode2004A&A...424..727P. 
  7. Jackson, E. S. et al. (May 1957), "The Orbits of the Spectroscopic Binaries Omicron Tauri, Xi Cancri, and Mu Ursae Majories", Astrophysical Journal 125: 712, doi:10.1086/146345, Bibcode1957ApJ...125..712J. 
  8. 8.0 8.1 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode2012MNRAS.427..343M. 
  9. "ksi Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ksi+Cnc. 
  10. 10.0 10.1 "Naming Stars". IAU.org. https://www.iau.org/public/themes/naming_stars/. 
  11. Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
  12. Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York, NY: Dover Publications Inc., p. 114, ISBN 0-486-21079-0, https://archive.org/details/starnamestheirlo00alle/page/114, retrieved 2010-12-12. 
  13. Rhoads, Jack W. (November 15, 1971), Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars, Jet Propulsion Laboratory, California Institute of Technology, https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720005197_1972005197.pdf. 
  14. "IAU Working Group on Star Names (WGSN)". https://www.iau.org/science/scientific_bodies/working_groups/280/. 
  15. "WG Triennial Report (2015–2018) – Star Names". p. 5. https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf.