HAT-P-19

HAT-P-19 is a K-type main-sequence star about 658 light-years away. The star is old yet metal-enriched, having amount of heavy elements 250% of solar abundance.^[5] A survey in 2012 failed to find any stellar companions to HAT-P-19.^[7]

HAT-P-19

Observation data Epoch J2000      Equinox J2000
Constellation	Andromeda[1]
Right ascension	00h 38m 04.0136s[2]
Declination	+34° 42′ 41.554″[2]
Apparent magnitude (V)	12.901[3]
Characteristics
Evolutionary stage	main sequence[2]
Spectral type	K1V[3]
Astrometry
Radial velocity (Rv)	−19.61±0.66[2] km/s
Proper motion (μ)	RA: −26.745(11) mas/yr[2] Dec.: −32.568(10) mas/yr[2]
Parallax (π)	4.9567±0.0137 mas[2]
Distance	658 ± 2 ly (201.7 ± 0.6 pc)
Details[4]
Mass	0.863+0.029 −0.025 M☉
Radius	0.851±0.013 R☉
Luminosity	0.37+0.08 −0.06[5] L☉
Surface gravity (log g)	4.514+0.019 −0.017 cgs
Temperature	5049+42 −65 K
Metallicity	0.283+0.081 −0.079
Rotation	14.66±0.03 d[5]
Rotational velocity (v sin i)	0.7±0.5[5] km/s
Age	8.8±5.2[5] Gyr
Other designations
Gaia DR2 3654266795168165128, 2MASS J00380401+3442416[6]
Database references
SIMBAD	data

Planetary system

In 2010 a transiting hot Saturn-sized planet was detected.^[3] Its equilibrium temperature is 984±10 K,^[8] and it is grey in color.^[9]

The transit-timing variation measurements in 2015 and 2018 did not detect additional planets in the system.^[10][11]

Size comparison of HAT-P-19 b and Jupiter

The HAT-P-19 planetary system^[3][8]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	0.290±0.016 MJ	0.04649±	4.00878236+0.00000050 −0.00000049	0.084±0.041	88.67+0.41 −0.25°	1.089±0.018 RJ