Astronomers have validated their first exoplanet with the Habitable Zone Planet Finder instrument on the Hobby-Eberly Telescope, one of the world’s largest telescopes, located at The University of Texas at Austin’s McDonald Observatory.
About twice the size of Earth and possibly 12 times as massive, the planet could be similar to Neptune, but in miniature. Called G 9-40b, it orbits a small star called a red dwarf about 100 light-years from Earth. It completes a full orbit every six Earth days.
NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star’s habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. A team of scientists, including Andrew Vanderburg of The University of Texas at Austin, confirmed the find, called TOI 700 d, using NASA’s Spitzer Space Telescope and have modeled the planet’s potential environments to help inform future observations.
TOI 700 d is one of only a few Earth-size planets discovered in a star’s habitable zone so far. Others include several planets in the TRAPPIST-1 system and other worlds discovered by NASA’s Kepler Space Telescope.