WASP-58

WASP-58 is a binary star system in the constellation Lyra. It comprises a G-type main-sequence star and a red dwarf at a separation of 384 astronomical units. WASP-58 is slightly depleted in heavy elements, having 80% of the solar abundance of iron. The system is much older than the Sun at 12.80^+0.20
_−2.10 billion years. Based on parallax measurements, it lies at a distance of 960 light-years (290 parsecs).

WASP-58

Observation data Epoch J2000      Equinox J2000
Constellation	Lyra[1]
Right ascension	18h 18m 48.25296s[2]
Declination	+45° 10′ 19.2603″[2]
Apparent magnitude (V)	11.66[3]
Characteristics
Evolutionary stage	Main sequence
Spectral type	G2V[3]
Astrometry
Radial velocity (Rv)	−28.42±0.71[2] km/s
Proper motion (μ)	RA: 32.658 mas/yr[2] Dec.: 47.057 mas/yr[2]
Parallax (π)	3.3963±0.0112 mas[2]
Distance	960 ± 3 ly (294.4 ± 1.0 pc)
Orbit[4]
Primary	WASP-58A
Companion	WASP-58B
Semi-major axis (a)	1.281±0.002" (384±64 AU)
Details[5]
WASP-58A
Mass	0.940±0.100 M☉
Radius	1.17±0.13 R☉
Surface gravity (log g)	4.23±0.1[6] cgs
Temperature	6039±55[6] K
Metallicity [Fe/H]	-0.09±0.04 dex
Rotation	22.6+11.7 −6.1 d[7]
Rotational velocity (v sin i)	2.8±0.9 km/s
Age	12.80+0.20 −2.10 Gyr
WASP-58B
Temperature	3396±53[4] K
Other designations
TOI-1627, TIC 424435940, WASP-58, TYC 3525-76-1, 2MASS J18184825+4510192[8]
Database references
SIMBAD	data
Exoplanet Archive	data

Lithium was detected in the stellar spectrum of WASP-58A, making the star anomalous for its advanced age.^[3]

A multiplicity survey in 2015 detected a red dwarf stellar companion^[9] at a projected separation of 1.281±0.002″ to WASP-58A, and it was confirmed to be gravitationally bound in 2016.^[4]

Planetary system

In 2012 a transiting hot Jupiter planet, WASP-58b, was detected on a tight, circular orbit around the primary star WASP-58A.^[3] The planetary equilibrium temperature is 1270±80 K.^[3]

The WASP-58 planetary system^[5]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	0.899+0.074 −0.072 MJ	0.0562+0.0019 −0.0020	5.017180±0.000011	<0.044	87.4±1.5°	1.37±0.2 RJ