Kepler-78
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus | 
| Right ascension | 19h 34m 58.01374s | 
| Declination | +44° 26′ 53.9602″ | 
| Apparent magnitude (V) | 11.72 | 
| Characteristics | |
| Evolutionary stage | main sequence | 
| Spectral type | K2.5V | 
| Astrometry | |
| Proper motion (μ) | RA: +38.195 mas/yr Dec.: −16.309 mas/yr | 
| Parallax (π) | 8.0085±0.0104 mas | 
| Distance | 407.3 ± 0.5 ly (124.9 ± 0.2 pc) | 
| Details | |
| Mass | 0.779+0.032 −0.046 M☉ | 
| Radius | 0.7475+0.0077 −0.0078 R☉ | 
| Luminosity | 0.31 L☉ | 
| Surface gravity (log g) | 4.51 cgs | 
| Temperature | 5,058±50 K | 
| Metallicity [Fe/H] | −0.18±0.08 dex | 
| Rotation | 12.53 days | 
| Rotational velocity (v sin i) | 3.1 km/s | 
| Age | 240 Myr | 
| Other designations | |
| Kepler-78, KIC 8435766, TYC 3147-188-1, 2MASS J19345800+4426539 | |
| Database references | |
| SIMBAD | data | 
| KIC | data | 
Kepler-78 (formerly known as KIC 8435766) is a 12th magnitude star 407 light-years (125 parsecs) away in the constellation Cygnus. Initially classified as an eclipsing binary with orbital period 0.710015 days, it was later re-classified as a single star with significant interaction between star magnetosphere and close-in planet. The radius of the star is of about 74% of the Sun, and the effective temperature is about 5,100 K.