WASP-69, also named Wouri, is a

K-type main-sequence star A K-type main-sequence star, also referred to as a K-type dwarf or an orange dwarf, is a main-sequence (hydrogen-burning) star of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence star ...

away. Its surface temperature is 4782 K. WASP-69 is slightly enriched in heavy elements compared to the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

, with a

metallicity In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...

Fe/H index of 0.10, and is much younger than the Sun at 2 billion years. The data regarding

starspot Starspots are stellar phenomena, so-named by analogy with sunspots. Spots as small as sunspots have not been detected on other stars, as they would cause undetectably small fluctuations in brightness. The commonly observed starspots are in gene ...

activity of WASP-69 are inconclusive, but spot coverage of the

photosphere The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...

may be very high. Multiplicity surveys did not detect any stellar companions to WASP-69 as of 2020.

Nomenclature

The designation ''WASP-69'' indicates that this was the 69th star found to have a planet by the

Wide Angle Search for Planets WASP or Wide Angle Search for Planets is an international consortium of several academic organisations performing an ultra-wide angle search for exoplanets using transit photometry. The array of robotic telescopes aims to survey the entire sky, s ...

. In August 2022, this planetary system was included among 20 systems to be named by the third

NameExoWorlds NameExoWorlds (also known as IAU NameExoWorlds) is the name of various projects managed by the International Astronomical Union (I.A.U.) to encourage names to be submitted for astronomical objects, which would later be considered for official ad ...

project. The approved names, proposed by a team from

Cameroon Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the C ...

, were announced in June 2023. WASP-69 is named Wouri and its planet is named Makombé, after the Wouri and Makombé rivers.

Planetary system

In 2013, one planet, named WASP-69b, was discovered on a tight, circular orbit. Its equilibrium temperature is 886 K, but the measured terminator temperature is significantly higher by at least 200 K. The planet is losing mass at a moderate rate of 0.5 per billion years, not producing a visible cometary tail, although it was detected in 2024 and measured to be at least 7 times its own radius. 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. The sodium may originate from volcanic moons, not from the planet itself. By 2021, the presence of hazes in atmosphere of WASP-69b was confirmed, along with a solar or super-solar water abundance.

References

{{Stars of Aquarius Aquarius (constellation) Planetary transit variables K-type main-sequence stars Planetary systems with one confirmed planet J21000618-0505398 BD-05 5432 069 Wouri