Astronomers have announced the discovery of GJ 740 b, a super-Earth exoplanet just 36 light-years from our solar system. While likely rocky, this world orbits outside its star's habitable zone.
Astronomers detect exoplanets primarily through two methods: the transit technique and radial velocity. Transit involves monitoring a star's light curve for periodic dips caused by a planet passing in front of it from our viewpoint. Radial velocity examines a star's spectrum for signs of wobble, revealing gravitational tugs from orbiting planets that cause the star to shift toward or away from Earth.
Though not the most common method, radial velocity has confirmed more than 600 exoplanets out of over 4,000 known to date. Of these, 116 orbit red dwarfs—the galaxy's most abundant stars, which are smaller, cooler, and dimmer than the Sun.
Led by Borja Toledo-Padrón from the University of La Laguna in Spain, a team recently identified GJ 740 b around one such red dwarf, located 36 light-years from Earth. This super-Earth—defined as a planet with a mass between Earth's and about ten times that—is at least 2.96 times more massive than Earth.
GJ 740 b completes an orbit every 2.377 days at a distance of just 0.029 AU (1 AU equals the Earth-Sun distance of about 150 million km). This proximity places it outside the habitable zone, with an equilibrium temperature of 829 Kelvin—roughly 555°C.
Without a known radius, its exact composition remains uncertain, but its mass and tight orbit indicate a rocky planet.
Data also hints at a second planet in the system: potentially 100 times Earth's mass, orbiting once every nearly 10 years.
