Alpha Comae Berenices

α Comae Berenices
Map of the constellation Coma Berenices
α Comae Berenices (circled) in the constellation Coma Berenices
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Coma Berenices
Right ascension 13h 09m 59.285s[1]
Declination +17° 31′ 46.04″[1]
Apparent magnitude (V) 4.29 to 4.35
(combined)[2]
A: 4.85 / B: 5.53[3]
Characteristics
Spectral type A: F5V / B: F5V
(binary star)[4]
U−B color index −0.06[5]
B−V color index 0.45[5]
V−R color index 0.2[6]
R−I color index 0.2[6]
Astrometry
Radial velocity (Rv)−17.7±0.9[6] km/s
Proper motion (μ) RA: −433.13±0.70[1] mas/yr
Dec.: 141.24±0.51[1] mas/yr
Parallax (π)56.10 ± 0.89 mas[1]
Distance58.1 ± 0.9 ly
(17.8 ± 0.3 pc)
Absolute magnitude (MV)3.82[7]
Orbit[8]
Period (P)25.8696±0.008219 yr
Semi-major axis (a)0.67144±0.00033″
Eccentricity (e)0.51060±0.00061
Inclination (i)90.0501±0.0062°
Longitude of the node (Ω)12.2272±0.0098°
Periastron epoch (T)57056.84±0.36
Argument of periastron (ω)
(secondary)		100.563±0.026°
Details
A
Mass1.237[9] M☉
Luminosity1.72[10] L☉
Surface gravity (log g)4.19[11] cgs
Temperature6,365[11] K
Metallicity [Fe/H]−0.23[11] dex
B
Mass1.087[9] M☉
Luminosity1.75[10] L☉
Temperature6,378[10] K
Other designations
α Com, Alpha Comae Berenices, Alpha Com, 42 Comae Berenices, 42 Com, STF 1728, ADS 8804 , BD+18 2697, CCDM J13100+1732, GC 17833, Gliese 501, HIP 64241, IDS 13051+1803 AB, LTT 13802, NLTT 33105, PPM 129630, SAO 100443, WDS 13100+1732.[6][12][13]
A: HD 114378, HR 4968
B: HD 114379, HR 4969
Database references
SIMBADdata

Alpha Comae Berenices (α Comae Berenices, abbreviated Alpha Com, α Com) is a binary star in the constellation of Coma Berenices (Berenice's Hair), 17.8 parsecs (58 ly) away. It consists of two main sequence stars, each a little hotter and more luminous than the Sun.

Alpha Comae Berenices is said to represent the crown worn by Queen Berenice. The two components are designated Alpha Comae Berenices A (officially named Diadem /ˈdaɪədɛm/, the traditional name for the system)[14] and B.

  1. ^ a b c d e Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  2. ^ NSV 6116, database entry, New Catalogue of Suspected Variable Stars, the improved version, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line September 3, 2008.
  3. ^ Cite error: The named reference orb was invoked but never defined (see the help page).
  4. ^ Diadem Archived 2008-05-11 at the Wayback Machine, Jim Kaler, Stars. Accessed on line September 3, 2008.
  5. ^ a b HR 4968, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 3, 2008.
  6. ^ a b c d Cite error: The named reference sb0 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Reiners2006 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Muterspaugh2015 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference pavlovic was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference brummelaar was invoked but never defined (see the help page).
  11. ^ a b c Cite error: The named reference pastel was invoked but never defined (see the help page).
  12. ^ HD 114378 -- Star in double system, database entry, SIMBAD, accessed on line September 3, 2008.
  13. ^ HD 114379 -- Star in double system, database entry, SIMBAD, accessed on line September 3, 2008.
  14. ^ "Naming Stars". IAU.org. Retrieved 16 December 2017.