20 Cancri

This article is about d¹ Cancri. For other stars with this Bayer designation, see d Cancri.

20 Cancri

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cancer
Right ascension	08^h 23^m 21.84287^s[1]
Declination	+18° 19′ 55.7825″[1]
Apparent magnitude (V)	5.94[2]
Characteristics
Evolutionary stage	main sequence[3]
Spectral type	A9 V[3]
B−V color index	0.175[2]
Astrometry
Radial velocity (Rv)	+35.8±2.9[4] km/s
Proper motion (μ)	RA: −51.953[1] mas/yr Dec.: −19.416[1] mas/yr
Parallax (π)	8.7606 ± 0.0986 mas[1]
Distance	372 ± 4 ly (114 ± 1 pc)
Absolute magnitude (MV)	+0.63[2]
Details
Mass	2.41±0.10[3] M☉
Radius	3.7[1] R☉
Luminosity	59.9+19.9 −15.0[3] L☉
Surface gravity (log g)	3.62[1] cgs
Temperature	7,907±73[3] K
Metallicity [Fe/H]	−0.30[1] dex
Rotational velocity (v sin i)	50[3] km/s
Age	700[1] Myr
Other designations
d^1 Cnc, 20 Cnc, BD+18°1930, FK5 1220, HD 70569, HIP 41117, HR 3284, SAO 97781[5]
Database references
SIMBAD	data

20 Cancri is an astrometric binary^[6] star system in the constellation Cancer, located about 372 light-years away from the Sun. This system has the Bayer designation d¹ Cancri; 20 Cancri is the Flamsteed designation.^[5] It is just visible to the naked eye under good viewing conditions, appearing as a dim, white-hued star with an apparent visual magnitude of 5.94.^[2] The pair are moving further from the Earth with a heliocentric radial velocity of +36 km/s,^[4] and are members of the Hyades Supercluster.^[7]

The visible component of this system is an ordinary A-type main-sequence star with a stellar classification of A9 V,^[3] which indicates it is generating energy by hydrogen fusion at its core. It has 2.4 times the mass of the Sun and is radiating 60 times the Sun's luminosity from its photosphere at an effective temperature of 7,907 K.^[3]

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 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. Zorec, J.; Royer, F.; Asplund, Martin; Cassisi, Santi; Ramirez, Ivan; Melendez, Jorge; Bensby, Thomas; Feltzing, Sofia (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
5. "20 Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-02-25.
6. Makarov, V. V.; Kaplan, G. H. (May 2005), "Statistical Constraints for Astrometric Binaries with Nonlinear Motion", The Astronomical Journal, 129 (5): 2420–2427, Bibcode:2005AJ....129.2420M, doi:10.1086/429590.
7. Eggen, Olin J. (April 1996), "The Stellar Content of Star Stream I", Astronomical Journal, 111: 1615, Bibcode:1996AJ....111.1615E, doi:10.1086/117901.