15 Cancri

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
15 Cancri
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cancer
Right ascension 08h 13m 08.867s[1]
Declination +29° 39′ 23.53″[1]
Apparent magnitude (V) 5.62
Spectral type A0:V:spSiSr[2]
Variable type α2 CVn[3]
Radial velocity (Rv)25.0±0.8[4] km/s
Proper motion (μ) RA: −11.12±0.47[1] mas/yr
Dec.: −20.49±0.35[1] mas/yr
Parallax (π)4.77 ± 0.40[1] mas
Distance680 ± 60 ly
(210 ± 20 pc)
Primary15 Cancri A
Companion15 Cancri B
Period (P)635.73±0.53 days[note 1]
Eccentricity (e)0.55±0.08
Periastron epoch (T)2422045±18
Argument of periastron (ω)
Semi-amplitude (K1)
9.6±1.1 km/s
Surface gravity (log g)3.22±0.2[5] cgs
Temperature10080±200[5] K
Other designations
15 Cancri, BM Cnc, BD+30° 1664, HD 68351, HIP 40240, HR 3215, GSC 01939-01462[6]
Database references

15 Cancri (15 Cnc, BM Cancri, BM Cnc) is an α2 CVn variable star in the constellation Cancer. Its apparent magnitude is 5.62.

Radial velocity measurements taken at the Dominion Astrophysical Observatory in Victoria, British Columbia Canada in 1918 and 1919 led to the determination that 15 Cancri is a spectroscopic binary.[7] The first orbit was calculated in 1973 by Helmut Abt and Michael Snowden with a period of 585 days[8] however later measurements showed that the orbital period was 635 days.[4][note 1]


  1. ^ a b An alternate period of 475 days is possible but less likely.


  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.  Vizier catalog entry
  2. ^ Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". Astrophysical Journal Supplement. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. 
  3. ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S. 
  4. ^ a b c Stickland, D. J.; Weatherby, J. (1984). "Radial velocities of northern Mercury stars". Astronomy and Astrophysics Supplement Series. 57: 55–67. Bibcode:1984A&AS...57...55S. 
  5. ^ a b Khalack, V.; LeBlanc, F. (2015). "Project VeSElkA: Analysis of Balmer Line Profiles of Slowly Rotating Chemically Peculiar Stars". The Astronomical Journal. 150 (1). 2. arXiv:1505.08158Freely accessible. Bibcode:2015AJ....150....2K. doi:10.1088/0004-6256/150/1/2. 
  6. ^ SIMBAD, 15 Cancri (accessed 2012 March 20)
  7. ^ Plaskett, J. S.; et al. (1919). "Fourth list of spectroscopic binaries". Journal of the Royal Astronomical Society of Canada. 13: 372–378. Bibcode:1919JRASC..13..372P. 
  8. ^ Abt, Helmut A.; Snowden, Michael S. (1973). "The Binary Frequency for AP Stars". Astrophysical Journal Supplement. 25: 137–162. Bibcode:1973ApJS...25..137A. doi:10.1086/190265.