| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 19h 47m 50.4746s[2] |
| Declination | +46° 02′ 03.500″[2] |
| Apparent magnitude (V) | 14.3[3] |
| Characteristics | |
| Spectral type | F7V[4] |
| Astrometry | |
| Proper motion (μ) | RA: 3.894(18)mas/yr[2] Dec.: −2.345(17)mas/yr[2] |
| Parallax (π) | 0.9316±0.0139 mas[2] |
| Distance | 3,500 ± 50 ly (1,070 ± 20 pc) |
| Details[4] | |
| Mass | 1.29+0.06 −0.07 M☉ |
| Radius | 1.40±0.10 R☉ |
| Surface gravity (log g) | 4.25±0.06 cgs |
| Temperature | 6350±100 K |
| Metallicity[Fe/H] | 0.10±0.14 dex |
| Rotation | 4.464±0.013 days[5] |
| Rotational velocity (v sin i) | 16±2.5 km/s |
| Age | 2.1+0.8 −0.9 Gyr |
| Other designations | |
| KOI-423,KIC 9478990,2MASS J19475046+4602034,Gaia DR2 2080168561154800384 | |
| Database references | |
| SIMBAD | data |
| KIC | data |
Kepler-39 (2MASS J19475046+4602034) is anF-typemain sequence star located in the constellationCygnus. It is located about 3,500 light-years (1,070 parsecs) away.[2] One knownsubstellar companion orbits it,Kepler-39b.[6]
Kepler-39b is generally considered abrown dwarf rather than a planet since it does not meet the standarddefinition of planet. Some authorities such as theExtrasolar Planets Encyclopaedia and theNASA Exoplanet Archive include it among their list of confirmed planets.[3][7]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 20.1+1.3 −1.2 MJ | 0.164±0.003 | 21.087210±0.000037 | 0.112±0.057 | 89.07±0.22° | 1.24+0.09 −0.10 RJ |
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