67 Cancri

67 Cancri is a wide binary star^[9] system in the zodiac constellation of Cancer, located 195^[1] light years away from the Sun. It is just visible to the naked eye as a faint, white-hued star with a combined apparent magnitude of 6.07.^[2] The binary nature of this system was discovered by James South and John Herschel.^[3] As of 2007, the two components have an angular separation of 103.9″, corresponding to a projected separation of 6,100 AU.^[9] They are moving further from the Earth with a heliocentric radial velocity of +12 km/s.^[5]

67 Cancri

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cancer
Right ascension	09h 01m 48.83393s[1]
Declination	+27° 54′ 09.3505″[1]
Apparent magnitude (V)	6.07[2] (6.08 + 9.22)[3]
Characteristics
Evolutionary stage	main sequence
Spectral type	A8 Vn[4]
B−V color index	0.243±0.008[2]
Astrometry
Radial velocity (Rv)	+12.0±4.3[5] km/s
Proper motion (μ)	RA: −57.037[1] mas/yr Dec.: −80.127[1] mas/yr
Parallax (π)	16.7647 ± 0.1550 mas[1]
Distance	195 ± 2 ly (59.6 ± 0.6 pc)
Absolute magnitude (MV)	2.25[2]
Details
67 Cnc A
Mass	1.89[6] M☉
Radius	1.90+0.07 −0.14[1] R☉
Luminosity	10.465+0.111 −0.112[1] L☉
Surface gravity (log g)	4.35[6] cgs
Temperature	7,982±271[6] K
Rotational velocity (v sin i)	105[7] km/s
Age	867[6] Myr
Other designations
67 Cnc, BD+28°1674, HD 77190, HIP 44342, HR 3589, SAO 80585, WDS 09014+3215[8]
Database references
SIMBAD	data

The primary, designated component A, is an A-type main-sequence star with a stellar classification of A8 Vn.^[4] The 'n' notation indicates "nebulous" lines due to rapid rotation. It is a shell star,^[10] with weak shell lines of singly-ionized titanium being detected in the near ultraviolet in 1970. These may have come from a sporadic mass loss event.^[11] Uesugi and Fukuda (1970) gave a projected rotational velocity estimate of 105^[7] km/s for the star, although Abt et al. (1997) suggested it could be as high as 205 km/s.^[11]

67 Cancri A is about 867^[6] million years old with 1.89^[6] times the mass of the Sun and 1.90^[1] times the Sun's radius. It is radiating 10.5^[1] times the Sun's luminosity from its photosphere at an effective temperature of 7,982 K.^[6]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
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, S2CID 119257644.
3. Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
4. Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
6. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
7. Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory, University of Kyoto, Bibcode:1970crvs.book.....U.
8. "67 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-09.
9. Trilling, D. E.; et al. (April 2007), "Debris disks in main-sequence binary systems", The Astrophysical Journal, 658 (2): 1264–1288, arXiv:astro-ph/0612029, Bibcode:2007ApJ...658.1289T, doi:10.1086/511668, S2CID 14867168.
10. Hauck, B.; Jaschek, C. (2000), "A-shell stars in the Geneva system", Astronomy and Astrophysics, 354: 157, Bibcode:2000A&A...354..157H.
11. Abt, Helmut A.; et al. (September 1997), "Hot Inner Disks that Appear and Disappear Around Rapidly Rotating A-Type Dwarfs", The Astrophysical Journal, 487 (1): 365–369, Bibcode:1997ApJ...487..365A, doi:10.1086/304603.