Zeta Cygni

Zeta Cygni / CCDM J21129+3014B [1][2]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cygnus
Right ascension 21h 12m 56.1862s / 21h 12m 53.9ss
Declination +30° 13′ 36.897″ / +30° 12′ 36″
Apparent magnitude (V) 3.20 / 11.6
Characteristics
Spectral type G8III / ?
U−B color index +0.76 / ?
B−V color index +0.99 / ?
Astrometry
Radial velocity (Rv) 17.4 / ? km/s
Proper motion (μ) RA: 6.87 / ? mas/yr
Dec.: -68.12 / ? mas/yr
Parallax (π) 21.62 ± 0.63 mas
Distance 151 ± 4 ly
(46 ± 1 pc)
Details
Mass 3 / 2.5 M
Radius ? R
Surface gravity (log g) ?
Luminosity ? L
Temperature 7125 K
Metallicity ?
Rotation ?
Age 400 million years
Other designations
Zeta Cygni, 64 Cygni, HR 8115, BD+29°4348, HD 202109, SAO 71070, HIP 104732, GC 29661, GSC 02702-02764, CCDM J21129+3014
Database references
SIMBAD data

Zeta Cygni (ζ Cyg) and CCDM J21129+3014B form a binary star system in the constellation Cygnus, approximately 151 light-years away from Earth.

The main star, 3rd magnitude Zeta Cygni, is a yellow star of the spectral type G8III. It has a radius 14.7 times that of our Sun and shines 119 times brighter in comparison. Its most likely status is as a core-helium fusing giant star, although it could be in transition to gianthood with a tranquil helium core. Assuming the former, it has a mass 3.0 solar masses and an age of 400 million years. Zeta Cygni has an abundance of barium, and other heavy chemical elements, in its atmosphere.[1][3]

Zeta Cygni has a 12th magnitude companion, assumed to be a white dwarf. It orbits every 6489 days, or every 17.8 years. A theoretical study shows the system started off with solar masses of 3.0 and 2.5, but the more massive star lost some of its mass in becoming a white dwarf. It sent half a solar mass to Zeta Cygni, along with the heavy chemical elements it possesses today.[3]

References

Citations

  1. ^ a b "Simbad Query Result". Simbad. http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=CCDM+J21129%2B3014A&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id. Retrieved October 18, 2007. 
  2. ^ "Simbad Query Result". Simbad. http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=CCDM+J21129%2B3014B&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id. Retrieved October 18, 2007. 
  3. ^ a b ""Zeta Cyg"". http://www.astro.uiuc.edu/~kaler/sow/zetacyg.html. Retrieved October 17, 2007.