Astronomy:82 Cancri

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Short description: Star in the constellation Cancer
82 Cancri
Cancer constellation map.svg
Red circle.svg
Location of 82 Cancri (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Cancer
Right ascension  09h 15m 13.85196s[1]
Declination +14° 56′ 29.4401″[1]
Apparent magnitude (V) +5.33[2]
Characteristics
Spectral type K1 III[3]
U−B color index +1.31[2]
B−V color index +1.32[2]
Astrometry
Radial velocity (Rv)+27.49±0.19[4] km/s
Proper motion (μ) RA: −40.874[1] mas/yr
Dec.: −11.835[1] mas/yr
Parallax (π)6.0793 ± 0.1222[1] mas
Distance540 ± 10 ly
(164 ± 3 pc)
Absolute magnitude (MV)−0.98[5]
Details
Mass2.56±0.13[6] M
Radius31.01+1.09
−3.52
[1] R
Luminosity307.4±7.3[1] L
Temperature4,340+270
−74
[1] K
Metallicity [Fe/H]−0.195±0.099[7] dex
Rotational velocity (v sin i)1.3±1.0[8] km/s
Other designations
π2 Cnc, 82 Cancri, BD+15° 2009, FK5 2733, HD 79554, HIP 45410, HR 3669, SAO 98456[9]
Database references
SIMBADdata

82 Cancri is a solitary,[3] orange-hued star in the zodiac constellation of Cancer. It has the Bayer designation Pi2 Cancri, which is Latinized from π2 Cancri; 82 Cancri is the star's Flamsteed designation. The star lies just a degree to the south of the ecliptic.[10] With an apparent visual magnitude of +5.33,[2] it is dimly visible to the naked eye on a dark night. This star is located at a distance of approximately 540 light years from the Sun based on parallax. At that range, the visual magnitude is diminished by an extinction of 0.10 magnitudes due to interstellar dust.[11] It is drifting further away with a radial velocity of +27 km/s.[4]

This is an evolved K-type giant star with a stellar classification of K1 III,[3] having exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. The star currently has 31[1] times the girth of the Sun and is spinning slowly with a projected rotational velocity. It is radiating over 300 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,340 K.[1] Based on its abundance of iron, the star has a lower abundances of heavier elements than the Sun.[7]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Rybka, E. (1969), "The corrected magnitudes and colours of 278 stars near S.A. 1-139 in the UBV system", Acta Astronomica 19: 229, Bibcode1969AcA....19..229R. 
  3. 3.0 3.1 3.2 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  4. 4.0 4.1 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. 
  5. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  6. Kervella, Pierre et al. (March 2019), "Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly", Astronomy & Astrophysics 623: 23, doi:10.1051/0004-6361/201834371, A72, Bibcode2019A&A...623A..72K 
  7. 7.0 7.1 Taylor, B. J. (February 1999), "Catalogs of temperatures and [Fe/H] averages for evolved G and K stars", Astronomy and Astrophysics Supplement 134 (3): 523–524, doi:10.1051/aas:1999153, Bibcode1999A&AS..134..523T. 
  8. De Medeiros, J. R. et al. (2014), "A catalog of rotational and radial velocities for evolved stars", Astronomy and Astrophysics 561: A126, doi:10.1051/0004-6361/201220762, Bibcode2014A&A...561A.126D. 
  9. "pi.02 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=pi.02+Cnc. 
  10. Sinnott, Roger W.; Perryman, Michael A. C. (1997), Millennium Star Atlas, 2, Sky Publishing Corporation and the European Space Agency, p. 711, ISBN 0-933346-83-2. 
  11. Famaey, B. et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics 430 (1): 165–186, doi:10.1051/0004-6361:20041272, Bibcode2005A&A...430..165F.