Kepler-40
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 47m 15.2874s |
| Declination | +47° 31′ 35.665″ |
| Apparent magnitude (V) | 14.58 (± 0.02) |
| Characteristics | |
| Evolutionary stage | subgiant star |
| Spectral type | F5IV |
| V−R color index | -0.31 |
| R−I color index | 0.87 |
| J−H color index | 0.242 |
| J−K color index | 0.266 |
| Astrometry | |
| Proper motion (μ) | RA: −1.469(22) mas/yr Dec.: −6.768(20) mas/yr |
| Parallax (π) | 0.4550±0.0168 mas |
| Distance | 7,200 ± 300 ly (2,200 ± 80 pc) |
| Details | |
| Mass | 1.48 (±0.06) M☉ |
| Radius | 2.13 (± 0.06) R☉ |
| Surface gravity (log g) | 3.812+0.048 −0.017 cgs |
| Temperature | 6510 (± 100) K |
| Metallicity | 0.10 +0.15 −0.10 |
| Age | 2.8 (± 0.3) Gyr |
| Other designations | |
| KIC 10418224, 2MASS 19471528+4731357, KOI-428 | |
| Database references | |
| SIMBAD | data |
Kepler-40, formerly known as KOI-428, is an F-type star in the constellation Cygnus. Kepler-40 is known to host at least one planet, Kepler-40b. The star is approximately 1.5 times more massive than the Sun, and is over two times its size; it was, at upon its discovery, the largest yet discovered with a transiting planet in its orbit. Kepler-40 was first noted as home to a possible transiting object by the Kepler spacecraft; the data on the system was released to the public. A team of French and Swiss scientists used follow-up data to determine the existence of the Hot Jupiter planet Kepler-40b, and later had their results published in a scientific journal on January 4, 2011.