WASP-69, also named Wouri, is a K-type main-sequence star 164 light-years (50 parsecs) away.[6] 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,[4] 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.[7]
Multiplicity surveys did not detect any stellar companions to WASP-69 as of 2020.[8]
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.[9] 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.[10]
Planetary system
In 2013, one planet, named WASP-69b,[6] was discovered on a tight, circular orbit.[2] Its equilibrium temperature is 886 K,[11] but the measured terminator temperature is significantly higher by at least 200 K.[7] The planet is losing mass at a moderate rate of 0.5 ME per billion years, not producing a visible cometary tail,[11] although it was detected in 2024 and measured to be at least 7 times its own radius.[12]
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.[7][13] The sodium may originate from volcanic moons, not from the planet itself.[14]
By 2021, the presence of hazes in atmosphere of WASP-69b was confirmed, along with a solar or super-solar water abundance.[15]
^ abcdefgAnderson, D. R.; Collier Cameron, A.; Delrez, L.; Doyle, A. P.; Faedi, F.; Fumel, A.; Gillon, M.; Gómez Maqueo Chew, Y.; Hellier, C.; Jehin, E.; Lendl, M.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Skillen, I.; Smalley, B.; Smith, A. M. S.; Southworth, J.; Triaud, A. H. M. J.; Turner, O. D.; Udry, S.; West, R. G. (2014). "Three newly discovered sub-Jupiter-mass planets: WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary". Monthly Notices of the Royal Astronomical Society. 445 (2): 1114–1129. arXiv:1310.5654. doi:10.1093/mnras/stu1737. S2CID54750890.
^France, Kevin; Arulanantham, Nicole; Fossati, Luca; Lanza, Antonino F.; Loyd, R. O. Parke; Redfield, Seth; Schneider, P. Christian (2018), "Far-ultraviolet Activity Levels of F, G, K, and M Dwarf Exoplanet Host Stars", The Astrophysical Journal Supplement Series, 239 (1): 16, arXiv:1809.07342, Bibcode:2018ApJS..239...16F, doi:10.3847/1538-4365/aae1a3, S2CID119368148