Zeta Cygni
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| Observation data Epoch J2000.0 |
|
|---|---|
| Constellation (pronunciation) |
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 |
| Details | |
| Mass | 3 / 2.5 M☉ |
| Radius | ? R☉ |
| Surface gravity (log g) | ? |
| Luminosity | ? L☉ |
| Temperature | 7125 K |
| Metallicity | ? |
| Rotation | ? |
| Age | 400 million years |
| Visual binary orbit | |
| Companion | Zeta Cygni B (CCDM J21129+3014B) |
| Period (P) | 17.8 yr |
| Semimajor axis (a) | 69" |
| Inclination (i) | 204° |
| Visual binary orbit | |
| Companion | Zeta Cygni C |
| Semimajor axis (a) | 90.4" |
| Inclination (i) | 300° |
| Visual binary orbit | |
| Companion | Zeta Cygni D |
| Semimajor axis (a) | 102.8" |
| Inclination (i) | 66° |
| Other designations | |
| 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]
[edit] References
- ^ a b Simbad Query Result. Simbad. Retrieved on October 18, 2007.
- ^ Simbad Query Result. Simbad. Retrieved on October 18, 2007.
- ^ a b "Zeta Cyg". Retrieved on October 17, 2007.
[edit] Stars components
| Database references | |
|---|---|
| SIMBAD | data |
| Database references | |
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| SIMBAD | data |
| Database references | |
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| SIMBAD | data |

