An artist's rendering of the Kepler-34 system, showing the binary star being orbited by Kepler-34b.
|Spectral type||G0V / G0V|
|Period (P)||27.7958103 (± 0.0000016) d|
|Semi-major axis (a)||0.22882 (± 0.00019) AU|
|Eccentricity (e)||0.52087 (± 0.00055)|
|Inclination (i)||89.8584 (± 0.0080)°|
|Mass||1.0479 (± 0.0033) M☉|
|Radius||1.1618 (± 0.0030) R☉|
|Temperature||5913 (± 130) K|
|Metallicity||-0.07 (± 0.15)|
|Mass||1.0208 (± 0.0022) M☉|
|Radius||1.0927 (± 0.0030) R☉|
Kepler-34 is an eclipsing binary star system in the constellation of Cygnus. Both stars have roughly the same mass as the Sun, therefore both are spectral class G. They are separated by 0.22 AU, and complete an eccentric orbit around a common center of mass every 27 days.
Kepler-34b is a gas giant that orbits the two stars in the Kepler-34 system. The planet is just over a fifth of Jupiter's mass and has a radius of 0.764 Jupiter radii. The planet completes a somewhat eccentric orbit every 288.822 days from a semimajor axis of just over 1 AU, the largest of any transiting planets at the time of its discovery. Such detection was possible as the planet transits both the stars, thus requiring fewer orbits to confirm the planet.
The majority of circumbinary planets were formed much further away from binary stars. They migrated to their current locations. From the physical growth rate of planets and account data on collisions, it is found that Kelper-34b would have grown where we find it now. 
(in order from star)
|b||0.220 MJ||1.0896||288.822||0.182||90.355°||0.764 RJ|
- Jean Schneider (2012). "Notes for star Kepler-34(AB)". Extrasolar Planets Encyclopaedia. Retrieved 7 April 2012.
- "Kepler-34b Helps Explain How Circumbinary Exoplanets Form". sci news. Retrieved 23 October 2014.