WASP-59

WASP-59 is a K-type main-sequence star about 379 light-years away in the constellation Pegasus. The star's age is essentially unconstrained by observations. WASP-59 is slightly depleted in heavy elements, having 70% of the solar abundance of iron.^[5] The star produces extremely low levels of ultraviolet light, indicating an absence of flare activity.^[6]

WASP-59

Observation data Epoch J2000      Equinox J2000
Constellation	Pegasus[1]
Right ascension	23h 18m 29.54747s[2]
Declination	+24° 53′ 21.4386″[2]
Apparent magnitude (V)	12.78[3]
Characteristics
Evolutionary stage	Main sequence
Spectral type	K5V[4]
Astrometry
Radial velocity (Rv)	−57.07±0.44[2] km/s
Proper motion (μ)	RA: −33.675 mas/yr[2] Dec.: −2.675 mas/yr[2]
Parallax (π)	8.6178±0.0140 mas[2]
Distance	378.5 ± 0.6 ly (116.0 ± 0.2 pc)
Details[5]
Mass	0.719±0.035 M☉
Radius	0.613±0.044 R☉
Surface gravity (log g)	4.72±0.06[4] cgs
Temperature	4650±150 K
Metallicity [Fe/H]	-0.15±0.11 dex
Rotational velocity (v sin i)	2.3±1.5 km/s
Age	7±7 Gyr
Other designations
TOI-5969, TIC 91051152, WASP-59, 2MASS J23182955+2453214[3]
Database references
SIMBAD	data
Exoplanet Archive	data

A multiplicity survey in 2015 did not detect any stellar companions to WASP-59.^[7]

Planetary system

In 2012 a transiting hot Jupiter planet, WASP-59b, was detected on a tight, mildly eccentric orbit.^[4]

Its equilibrium temperature is 670±35 K.^[4] The planet is unusually dense for a gas giant, representing an outlier on the mass-radius diagram.^[8]

The WASP-59 planetary system^[5]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	0.857+0.046 −0.047 MJ	0.0697±0.0011	7.919585±0.000010	0.101+0.046 −0.048	89.27±0.52°	0.775±0.068 RJ