An international team of scientists led by researchers from the Astrophysical Institute of the Canary Islands (IAC) has discovered the existence of two Earth-like planets orbiting the star GJ 1002, a red dwarf star not far from the Solar System. Both planets are in the star’s habitable zone.

“Nature seems to be trying to show us that Earth-like planets are very common. With these two we now know 7 planetary systems located close enough to the Sun,” explains Alejandro Suárez Mascareño, an IAC researcher and first author of the study published in the journal Nature. Astronomy and Astrophysics.

The newly discovered exoplanets orbit the star GJ 1002, located 16 light-years from the Solar System. Both have a mass similar to that of Earth and are in the habitable zone of their stars. GJ 1002b, the interior of the two, takes a little over 10 days to complete one orbit around the star, while GJ 1002c takes just over 21 days. “GJ 1002 is a red dwarf with a mass only one-eighth the mass of the Sun. It is a very cold, faint star. This means that its habitable zone is very close to the star,” explains Vera Maria Pasegger, co-author of the paper and IAC researcher.

The star’s proximity to our Solar System means that the two planets, particularly GJ 1002c, are excellent candidates for characterizing their atmospheres based on reflected light or thermal radiation. “The future ANDES spectrograph for the ELT telescope at ESO, which includes IAC, could investigate the presence of oxygen in the atmosphere of the GJ 1002c,” says IAC researcher Jonay I. González Hernández, one of the paper’s authors. . Additionally, both planets meet the requirements to be targets for the future LIFE mission currently being studied.

The discovery was made during a collaboration between two consortiums of ESPRESSO and CARMENES instruments. GJ 1002 was observed by CARMENES between 2017 and 2019 and by ESPRESSO between 2019 and 2021. “Because of its low temperature, the visible light from GJ 1002 is too weak to measure velocity fluctuations with most spectrographs,” says Ignacy Ribas. , researcher and director of the Space Sciences Institute (ICE-CSIC) Institute of Spatial Studies of Catalonia (IEEC). CARMENES has a sensitivity over a wide range of near-infrared wavelengths that surpasses that of other spectrographs designed to detect changes in stellar velocities, allowing it to study GJ 1002 from the 3.5-metre telescope at the Calar Alto Observatory.

The combination of the light-gathering power of ESPRESSO and ESO’s VLT 8m telescopes allowed measurements to be made with an accuracy of just 30 cm/sec unattainable with any other instrument in the world. “If they had undertaken this task independently, the two groups each would have had a lot of difficulty. Working together, we were able to go much further than we could by acting independently,” says Suárez Mascareño. Source