The newly discovered planets orbit the star GJ 1002, which is less than 16 light-years away from the Solar System.
“Nature seems determined to show us that Earth-like planets are very common. With these two, we now know 7 in planetary systems quite close to the Sun,” explains Alejandro Suárez Mascareño, researcher at the IAC, who is the first author on study accepted for publication in Astronomy & Astrophysics.
The newly discovered planets orbit the star GJ 1002, which is less than 16 light-years away from the Solar System. Both have Earth-like masses, and are in their star’s habitable zone. GJ 1002b, the inner of the two, takes just over 10 days to complete an orbit around the star, while GJ 1002c takes just over 21 days. “GJ 1002 is a red dwarf star, with only one eighth of the mass of the Sun. It is a very cool and faint star. This means that its habitable zone is very close to the star”, explains Vera María Passegger, co-author of the article and researcher at the IAC.
The proximity of the star to our Solar System implies that the two planets, especially GJ 1002c, are excellent candidates for the characterization of their atmospheres from their reflected light or thermal emission. “The future ANDES spectrograph for the ESO ELT telescope in which the IAC participates, could study the presence of oxygen in the atmosphere of GJ 1002c”, notes Jonay I. González Hernández, an IAC researcher who is co-author of the article. . In addition, both planets meet the necessary characteristics to be targets for the future LIFE mission, which is currently under study.
The discovery was made during a collaboration between the consortia of the two ESPRESSO and CARMENES instruments. GJ 1002 was observed by CARMENES between 2017 and 2019, and by ESPRESSO between 2019 and 2021. “Due to its low temperature, the visible light of GJ 1002 is too weak to measure its velocity variations with most spectrographs,” says Ignasi Ribas. , researcher at the Institute of Space Sciences (ICE-CSIC) and director of the Institute of Space Studies of Catalonia (IEEC). CARMENES has a sensitivity over a wide range of near-infrared wavelengths superior to that of other spectrographs designed to detect variations in the velocities of stars, and this allowed it to study GJ 1002, from the 3 .5 m from the Calar Alto observatory.
The combination of ESPRESSO and the light-gathering power of ESO’s VLT 8m telescopes made it possible to make measurements with a precision of only 30 cm/s, which cannot be achieved with any other instrument in the world. “Either of the two groups would have had a lot of difficulty if they had approached this job independently. Together we have been able to go much further than we would have done acting independently”, says Suárez Mascareño.
Two temperate Earth-mass planets orbiting the nearby star GJ 1002, Astronomy and Astrophysics
Astrobiology