WASP-29

WASP-29 is a binary star system 285 light-years (87 parsecs) away in the constellation of Phoenix. The primary star is a K-type main-sequence star. Its comoving companion, a red dwarf star, was discovered in 2021.^[4] The star system kinematically belongs to the thin disk of the Milky Way.^[6] The primary is an old star with small starspot activity and low x-ray flux.^[7]

WASP-29

Observation data Epoch J2000      Equinox J2000
Constellation	Phoenix[1]
Right ascension	23h 51m 31.08391s[2]
Declination	−39° 54′ 24.2582″[2]
Apparent magnitude (V)	11.33[3]
Characteristics
WASP-29A
Evolutionary stage	main sequence star
Spectral type	K4V[4]
B−V color index	0.82
J−H color index	0.478
J−K color index	0.570
WASP-29B
Spectral type	M3V[4]
Astrometry
Radial velocity (Rv)	24.31±0.20[2] km/s
Proper motion (μ)	RA: −56.767(14) mas/yr[2] Dec.: −88.988(13) mas/yr[2]
Parallax (π)	11.4349±0.0151 mas[2]
Distance	285.2 ± 0.4 ly (87.5 ± 0.1 pc)
Position (relative to WASP-29A)[4]
Component	WASP-29B
Epoch of observation	2021
Angular distance	125.2″
Projected separation	10994 AU
Details[5]
WASP-29A
Mass	0.825±0.033 M☉
Radius	0.808±0.044 R☉
Surface gravity (log g)	4.5±0.2 cgs
Temperature	4800±150 K
Metallicity [Fe/H]	0.11±0.14 dex
Rotational velocity (v sin i)	1.50±0.60 km/s
Age	14+0 −7 Gyr
WASP-29B
Mass	0.38[4] M☉
Other designations
CD−40 15273, TOI-192, TIC 183537452, WASP-29, TYC 8015-1020-1, 2MASS J23513108-3954241, DENIS J235131.0-395423[3]
WASP-29A: Gaia DR3 6534414719318886144
WASP-29B: Gaia DR3 6534426740931264896
Database references
SIMBAD	data

Planetary system

The "hot Saturn" class planet WASP-29b was discovered around WASP-29 in 2010.^[6] The planet would have an equilibrium temperature of 960±30 K.^[8] The planetary atmosphere has abundant carbon monoxide but likely lacks methane^[9] and sodium,^[10] although the high and dense cloud deck of WASP-29b prevents high-quality spectroscopic measurements.^[11]

A study in 2018 revealed the stability of planetary orbits in the habitable zone of WASP-29 is significantly affected by the WASP-29b planet.^[12]

The WASP-29 planetary system^[8]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	0.243+0.020 −0.019 MJ	0.0470±0.0025	3.92271218(25)	<0.059[5]	89.468+0.018 −0.017°	0.775±0.031 RJ