Theta Cancri

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Theta Cancri
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cancer
Right ascension 08h 31m 35.72962s[1]
Declination +18° 05′ 39.9160″[1]
Apparent magnitude (V) +5.323[2]
Spectral type K5 III[3]
U−B color index +1.949[2]
B−V color index +1.565[2]
Radial velocity (Rv) +44.47±0.19[4] km/s
Proper motion (μ) RA: −60.85[1] mas/yr
Dec.: −56.14[1] mas/yr
Parallax (π) 7.86 ± 0.29[1] mas
Distance 410 ± 20 ly
(127 ± 5 pc)
Other designations
θ Cnc, 31 Cancri, BD+18° 1963, FK5 2667, HD 72094, HIP 41822, HR 3357, SAO 97881[5]
Database references

Theta Cancri (θ Cancri) is a multiple star[6][3] system in the zodiac constellation of Cancer, 410 light years from Earth. The primary, component A, is classified as an orange K-type giant with an apparent magnitude of +5.32.[2] Since it is near the ecliptic, it can be occulted by the Moon[7] and, very rarely, by planets.


  1. ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Gutierrez-Moreno, Adelina; et al. (1966), A System of photometric standards, 1, Publicaciones Universidad de Chile, Department de Astronomy, pp. 1–17, Bibcode:1966PDAUC...1....1G. 
  3. ^ a b Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x. 
  4. ^ 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, Bibcode:2012A&A...546A..61D, arXiv:1208.3048Freely accessible, doi:10.1051/0004-6361/201219219, A61. 
  5. ^ "tet Cnc -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-06-19. 
  6. ^ Hartkopf, W. I.; McAlister, H. A. (January 1984), "Binary stars unresolved by speckle interferometry. III", Astronomical Society of the Pacific, Publications, 96: 105−116, Bibcode:1984PASP...96..105H, doi:10.1086/131309. 
  7. ^ White, Nathaniel M.; Feierman, Barry H. (September 1987), "A Catalog of Stellar Angular Diameters Measured by Lunar Occultation", Astronomical Journal, 94: 751, Bibcode:1987AJ.....94..751W, doi:10.1086/114513.