At a distance of 137 light-years, there is a M dwarf star TOI-715, which is older than the Sun, and has now been discovered by the Transiting Exoplanet Survey Satellite (TESS) with an orbital period of 193 days of habitable zone planets.
TOI-715 is an ordinary red dwarf with a spectral type of M4, about a quarter of the mass and radius of the Sun, but about 6.6 billion years old, which is older than the Sun.
Recently, the team of astronomer Georgina Dransfield at the University of Birmingham discovered that TOI-715 hosts a super-Earth, TOI-715B, and another smaller terrestrial planet candidate, TOI-715C, using data from NASA's Transiting Exoplanet Survey (TESS).
TOI-715b is close to the star, with a radius of about 1 Earth55 times, it takes only 19 days to orbit the parent star, but because the red dwarf is already dimmer than the Sun, TOI-715b is still in the stellar habitable zone, and its distance from the parent star allows the surface to maintain liquid water.
Regardless of whether TOI-715b is habitable or not, it should be able to tell us about exoplanets, photoevaporation, and the distribution of planets around red dwarfs; The system's other candidate planet, TOI-715C, is about Earth's size and would be the smallest habitable planet ever discovered by the TESS moon, if its existence is later confirmed.
Of course, the maintenance of surface water depends on the presence or absence of a proper atmosphere, which in turn depends largely on other characteristics of the planet, such as how massive it is.
Astronomers are looking forward to the follow-up attention from the Webb Space Telescope, which symbolizes the time to describe in detail the characteristics of exoplanetary atmospheres, observing the spectrum of exoplanets' atmospheres and determining their composition.
Header image**: NASA).