Kepler-63

Kepler-63 is a G-type main-sequence star about 638 light-years away. The star is much younger than the Sun, at 0.21 billion years. Kepler-63 is similar to the Sun in its concentration of heavy elements.

Kepler-63

Observation data Epoch J2000      Equinox J2000
Constellation	Cygnus[1]
Right ascension	19h 16m 54.2861s[2]
Declination	49° 32′ 53.451″[2]
Apparent magnitude (V)	12.02[3]
Characteristics
Evolutionary stage	Main sequence[2]
Spectral type	G2V[4]
Astrometry
Radial velocity (Rv)	−21.7±0.8[2] km/s
Proper motion (μ)	RA: 14.375[2] mas/yr Dec.: 23.336[2] mas/yr
Parallax (π)	5.1157±0.0096 mas[2]
Distance	638 ± 1 ly (195.5 ± 0.4 pc)
Details[5]
Mass	0.984+0.035 −0.040 M☉
Radius	0.901+0.027 −0.021 R☉
Luminosity	0.696+0.076 −0.059[3] L☉
Surface gravity (log g)	4.52±0.02 cgs
Temperature	5576±50 K
Metallicity [Fe/H]	0.05±0.08[3] dex
Rotation	5.4±0.009 days
Rotational velocity (v sin i)	5.6±0.8[3] km/s
Age	0.21±0.045 Gyr
Other designations
KOI-63, TYC 3550-458-1, 2MASS J19165428+4932535[6]
Database references
SIMBAD	data

The star is exhibiting strong starspot activity, with relatively cold (4700±300 K) starspots concentrated in two mid-latitude bands similar to the Sun,^[5] changing their position in a cycle with a period of 1.27±0.16 years.^[7] Due to high magnetic activity associated with its young age, Kepler-63 has a very hot corona heated to 8 million degrees, and produces over ten times the solar amount of x-rays than the Sun.^[8]

Multiplicity surveys did not detect any stellar companions to Kepler-63 by 2016.^[9]

Planetary system

In 2013 a transiting hot Jupiter planet b was detected on a tight orbit. The orbit is nearly polar to the equatorial plane of the star.^[3]

The Kepler-63 planetary system

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	< 0.377[8] MJ	0.080±0.002[8]	9.4341505±0.000001[5]	<0.45[3]	87.806+0.018 −0.019[5]°	0.54±0.02[8] RJ