Kepler-39

Kepler-39 (2MASS J19475046+4602034) is an F-type main sequence star located in the constellation Cygnus. It is located about 3,500 light-years (1,070 parsecs) away.^[2] One known substellar companion orbits it, Kepler-39b.^[6]

Kepler-39

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, Gaia DR2 2080168561154800384, 2MASS J19475046+4602034
Database references
SIMBAD	data
KIC	data

Planetary system

Kepler-39b is generally considered a brown dwarf rather than a planet since it does not meet the standard definition of planet. Some authorities such as the Extrasolar Planets Encyclopaedia and the NASA Exoplanet Archive include it among their list of confirmed planets.^[3][7]

The Kepler-39 planetary system^[4]

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