Astronomy:Nu Cancri

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Short description: Binary star system in the constellation Cancer
ν Cancri
Location of ν Cancri (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Cancer[1]
Right ascension  09h 02m 44.268s[2]
Declination +24° 27′ 10.39″[2]
Apparent magnitude (V) +5.46[3]
Characteristics
Evolutionary stage main sequence[4]
Spectral type A0 III[5]
U−B color index −0.10[3]
B−V color index −0.03[3]
Astrometry
Radial velocity (Rv)−15.6±0.7[6] km/s
Proper motion (μ) RA: −4.801[2] mas/yr
Dec.: −1.621[2] mas/yr
Parallax (π)7.2947 ± 0.1477[2] mas
Distance447 ± 9 ly
(137 ± 3 pc)
Absolute magnitude (MV)+0.05[1]
Orbit[7]
Period (P)1,401.4 ± 4.8 d (3.837 ± 0.013 yr)
Semi-major axis (a)≥ 138.3×106 km (0.924 astronomical unit|AU)
Eccentricity (e)0.35±0.17
Periastron epoch (T)2419687±63 JD
Argument of periastron (ω)
(secondary)
264±9°
Semi-amplitude (K1)
(primary)
7.7±1.3 km/s
Details
ν Cnc A
Mass2.12[4] M
Radius2.73[4] R
Luminosity125[4] L
Surface gravity (log g)3.86[4] cgs
Temperature10,000[4] K
Metallicity [Fe/H]−0.20±0.04[1] dex
Rotational velocity (v sin i)18.9±0.4[8] km/s
Age498[9] Myr
Other designations
ν Cnc, 69 Cancri, BD+25°2029, FK5 2714, HD 77350, HIP 44405, HR 3595, SAO 80595[10]
Database references
SIMBADdata

Nu Cancri is a binary star system[7] in the zodiac constellation of Cancer. Its name is a Bayer designation that is Latinised from ν Cancri, and abbreviated Nu Cnc or ν Cnc. This star is faintly visible to the naked eye with an apparent visual magnitude of +5.46.[3] Based upon an annual parallax shift of 8.31 mas as seen from the Earth,[2] the star is located roughly 447 light-years (137 pc) away from the Sun. It is drifting closer with a line of sight velocity of −16 km/s.[6]

The binary nature of this system was announced in 1973. This is a single-lined spectroscopic binary system with an orbital period of 3.8 years and an eccentricity of 0.35.[7] The primary, component A, is a white-hued A-type star with a stellar classification of A0 III.[5] It is a magnetic Ap star with a field strength of 846×10−4 T, showing abundance peculiarities in strontium, chromium and mercury.[8] This has been studied as a mercury-manganese star that has reached the end of its main sequence lifetime, although it has an unusually low abundance of mercury for a star of this type.[11] The star has 2.8 times the mass of the Sun and is radiating 93 times the Sun's luminosity from its photosphere at an effective temperature of 10,250 K.[8]

References

  1. 1.0 1.1 1.2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A.  XHIP record for this object at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940.  Gaia DR3 record for this source at VizieR.
  3. 3.0 3.1 3.2 3.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Glagolevskij, Yu. V. (2019). "On Properties of Main Sequence Magnetic Stars". Astrophysical Bulletin 74 (1): 66. doi:10.1134/S1990341319010073. Bibcode2019AstBu..74...66G. 
  5. 5.0 5.1 Royer, F. et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393 (3): 897–911, doi:10.1051/0004-6361:20020943, Bibcode2002A&A...393..897R. 
  6. 6.0 6.1 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. 
  7. 7.0 7.1 7.2 Abt, Helmut A.; Snowden, Michael S. (February 1973), "The Binary Frequency for AP Stars", Astrophysical Journal Supplement 25: 137, doi:10.1086/190265, Bibcode1973ApJS...25..137A. 
  8. 8.0 8.1 8.2 Wraight, K. T. et al. (February 2012), "A photometric study of chemically peculiar stars with the STEREO satellites - I. Magnetic chemically peculiar stars", Monthly Notices of the Royal Astronomical Society 420 (1): 757–772, doi:10.1111/j.1365-2966.2011.20090.x, Bibcode2012MNRAS.420..757W. 
  9. Kordopatis, G.; Schultheis, M.; McMillan, P. J.; Palicio, P. A.; De Laverny, P.; Recio-Blanco, A.; Creevey, O.; Álvarez, M. A. et al. (2023). "Stellar ages, masses, extinctions, and orbital parameters based on spectroscopic parameters of Gaia DR3". Astronomy and Astrophysics 669: A104. doi:10.1051/0004-6361/202244283. Bibcode2023A&A...669A.104K. 
  10. "nu. Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=nu.+Cnc. 
  11. Monier, Richard (May 2025), "Determination of the Abundance of Mercury from the Hg II Line at 5677.10 Å. XX. HD 77350", Research Notes of the AAS 9 (5): 124, doi:10.3847/2515-5172/addabd, 124, Bibcode2025RNAAS...9..124M.