An international scientific team 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. From these two we now know 7 planetary systems located close enough to the Sun,” explains Alejandro Suárez Mascareño, first author of the study and IAC researcher. accepted for publication Astronomy and Astrophysics.

The newly discovered planets orbit the star GJ 1002, located 16 light-years from the Solar System. They have a mass similar to that of Earth and are in the habitable zone of their star. 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 Paseger, a researcher at IAC and co-author of the paper.

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 upcoming ANDES spectrograph for the ELT telescope at ESO, which includes IAC, can investigate the presence of oxygen in the atmosphere of GJ 1002c,” says Jonay I. González Hernández, an IAC researcher and co-author of the paper. 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.

“Due to its low temperature, the visible light from the GJ 1002 is too weak to measure the velocity change with most spectrographs,” says Ignacy Ribas, a researcher and director of the Space Sciences Institute (ICE-CSIC). d’Estudis Espacials de Catalunya (IEEC).

CARMENES’ sensitivity over a wide range of near-infrared wavelengths exceeds that of other spectrographs designed to detect fluctuations in stellar velocities, enabling GJ 1002 to be studied through 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 made it possible to measure with an accuracy of just 30 cm/s, unattainable with any other instrument in the world.

“If they had undertaken this work independently, the two groups would have had a lot of trouble each. Together, we were able to go much further than we could have done by acting independently,” says Suárez Mascareño. Source