From Astronomy Magazine: https://astronomy.com/
Third exoplanet found around closest star to Earth
A little over four light-years away is Alpha Centauri, the closest star system to the Sun. And in August 2016, researchers announced they’d found a long-searched-for planet around Proxima Centauri, the smallest — and closest — component of this three-star system. Then, in January 2020, astronomers spotted a second world around Proxima Centauri. And now, the star’s family tree appears to be growing again: A third terrestrial planet has been found orbiting the nearest star to Earth.
A new addition
In a study published Feb. 10 in Astronomy & Astrophysics, astronomers announced the discovery of Proxima d. This tiny planet, weighing in at just one-quarter the mass of Earth, orbits Proxima Centauri every five days at a distance of some 2.5 million miles (4 million kilometers), or less than one-tenth the distance of Mercury from our own Sun. But because Proxima Centauri is a red dwarf with only about 12 percent the Sun’s mass and 14 percent its diameter, this puts Proxima d in the star’s habitable zone, where conditions are just right for liquid water to potentially exist on its surface.