WASP-69
Star in the constellation Aquarius
From Wikipedia, the free encyclopedia
WASP-69, also named Wouri, is a K-type main-sequence star 164 light-years (50 parsecs) away from Earth in the constellation Aquarius.[8] Its surface temperature is 4782±15 K. WASP-69 is slightly enriched in heavy elements compared to the Sun, with a metallicity Fe/H index of 0.10±0.01,[6] and is much younger than the Sun at 2 billion years. The data regarding starspot activity of WASP-69 are inconclusive, but spot coverage of the photosphere may be very high.[9]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius[1] |
| Right ascension | 21h 00m 06.19682s[2] |
| Declination | −05° 05′ 40.0349″[2] |
| Apparent magnitude (V) | 9.87±0.03[3] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | K5V[4] |
| Astrometry | |
| Radial velocity (Rv) | −9.83±0.13[2] km/s |
| Proper motion (μ) | RA: 33.778 mas/yr[2] Dec.: −93.581 mas/yr[2] |
| Parallax (π) | 19.8858±0.0170 mas[2] |
| Distance | 164.0 ± 0.1 ly (50.29 ± 0.04 pc) |
| Details | |
| Mass | 0.826±0.029[3] M☉ |
| Radius | 0.813[3] R☉ |
| Luminosity | 0.34[5] L☉ |
| Surface gravity (log g) | 4.59±0.02[6] cgs |
| Temperature | 4,782±15[6] K |
| Metallicity [Fe/H] | 0.10±0.01[6] dex |
| Rotation | 23.07 d[3] |
| Rotational velocity (v sin i) | 1.27±0.22[6] km/s |
| Age | 2[3] Gyr |
| Other designations | |
| Wouri, BD−05 5432, TOI-5823, TIC 248853232, WASP-69, TYC 5200-1560-1, GSC 05200-01560, 2MASS J21000618-0505398[7] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Multiplicity surveys did not detect any stellar companions to WASP-69 as of 2020.[10]
Nomenclature
The designation WASP-69 indicates that this was the 69th star found to have a planet by the Wide Angle Search for Planets.
In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project.[11] The approved names, proposed by a team from Cameroon, were announced in June 2023. WASP-69 is named Wouri and its planet is named Makombé, after the Wouri and Makombé rivers in Cameroon.[12]
Planetary system
In 2013, one planet, named WASP-69b,[8] was discovered on a tight, circular orbit.[3] Its equilibrium temperature is 886 K,[13] but the measured terminator temperature is significantly higher by at least 200 K.[9] The planet is losing mass at a moderate rate of 0.5 M🜨 per billion years,[13] producing a tail detected in 2024 and measured to be at least 7 times its own radius.[14]
The planetary atmosphere is extremely hazy and contains a partial cloud deck with cloud tops rising to a pressure of 100 Pa. Its composition is mostly hydrogen and helium, and sodium was also detected in low concentration.[9][15] The sodium may originate from volcanic moons, not from the planet itself.[16]
By 2021, the presence of hazes in atmosphere of WASP-69b was confirmed, along with a solar or super-solar water abundance.[17]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Makombé | 0.260±0.017 MJ | 0.04525±0.00053 | 3.8681382±0.0000017 | 0 | 86.71±0.20° | 0.945+0.007 −0.017[9] RJ |