ESPRESSO and CARMENES discover two potentially habitable exo-Earths around a star near the Sun

Artist's impression of two Earth-mass planets orbiting the star GJ 1002. Credit: Alejandro Suárez Mascareño and Inés Bonet (IAC)

Advertised on

An international scientific team led by researchers at the Instituto de Astrofísica de Canarias (IAC) has discovered the presence of two planets with Earth-like masses in orbit around the star GJ 1002, a red dwarf not far from the Solar System. Both planets are in the habitability zone of the star

“Nature seems bent on showing us that Earth-like planets are very common. With these two we now know 7 in planetary systems quite near to the Sun” explains Alejandro Suárez Mascareño, an IAC researcher, who is the first author of the study accepted for publication in Astronomy & Astrophysics.

The newly discovered planets orbit the star GJ 1002, which is at a distance of less than 16 light years from the Solar System. Both of them have masses similar to that of the Earth, and they are in the habitability zone of their star. GJ 1002b, the inner of the two, takes little more than 10 days to complete an orbit around the star, while GJ 1002c needs a little over 21 days. “GJ 1002 is a red dwarf star, with barely one eighth the mass of the Sun. It is quite a cool, faint star. This means that its habitability zone is very close to the star” explains Vera María Passegger, a co-author of the article and an IAC researcher.

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 based either on their reflected light, or on their thermal emission. “The future ANDES spectrograph for the ELT telescope at ESO in which the IAC is participating, could study the presence of oxygen in the atmosphere of GJ 1002c” notes Jonay I. González Hernández, an IAC researcher who is a co-author of the article. In addition, both planets satisfy the characteristics needed for them to be objectives for the future LIFE mission, which is presently in a study phase.

Infographic comparing the relative distance between the discovered planets and their star with the inner planets of the Solar System. The region marked in green represents the habitable zone of the two planetary systems. Design: Alejandro Suárez Mascareño (IAC). Planets of the Solar System: NASA

The discovery was made during a collaboration between the consortia of the two instruments ESPRESSO and CARMENES. 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 faint to measure its variations in velocity with the majority of spectrographs” says says Ignasi Ribas, researcher at the Institute of Space Sciences (ICE-CSIC) and director of the Institut d'Estudis Espacials de Catalunya (IEEC). CARMENES has a sensitivity over a wide range of near infrared wavelengths which is superior to those of other spectrographs aimed at detecting variations in the velocities of stars, and this allowed it to study GJ 1002, from the 3.5m telescope at Calar Alto observatory.

The combination of ESPRESSO, and the light gathering power of the VLT 8m telescopes at ESO allowed measurements to be made with an accuracy of only 30 cm/sec, not attainable with any other instrument in the world. “Either of the two groups would have had many difficulties if they had tackled this work independently. Jointly we have been able to get much further than we would have done acting independently” states Suárez Mascareño.

Other members of the IAC who have collaborated in this publication are the researchers Rafael Rebolo López, Víctor Sánchez Béjar and Enric Pallé.

Article: A. Suárez Mascareño et al: “Two temperate Earth-mass planets orbiting the nearby star GJ 1002”, Astronomy & Astrophysics, 2022. DOI:

Contact at the IAC:

Alejandro Suárez Mascareño, asm [at] (asm[at]iac[dot]es)

Jonay I. González Hernández, jonay [at] (jonay[at]iac[dot]es)

Related projects
Projects' name image
Exoplanets and Astrobiology
The search for life in the universe has been driven by recent discoveries of planets around other stars (known as exoplanets), becoming one of the most active fields in modern astrophysics. The growing number of new exoplanets discovered in recent years and the recent advance on the study of their atmospheres are not only providing new valuable
Pallé Bago
Vista superior de ESPRESSO ya instalado
ESPRESSO - Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observation
ESPRESSO is a fiber-fed, cross-dispersed, high resolution, Echelle spectrograph which can be operated with one or up to 4 Unit Telescopes (UTs) of ESO’s VLT.
Rebolo López
Illustration of the ANDES instrument (formerly known as HIRES) and its adressed scientific goals. (Credit: HIRES consortium)
ANDES - ArmazoNes high Dispersion Echelle Spectrograph
ANDES (ArmazoNes high Dispersion Echelle Spectrograph) is an instrument under study for ESO’s forthcoming Extremely Large Telescope (ELT). The contract to begin design studies for ANDES, formerly known as HIRES, was signed in 2016 by ESO. IAC is one of the more than 30 institutions in the ANDES consortium.
Rebolo López
Jonay Isai
González Hernández
Related news
Five exoplanet system
International research, led by the Instituto de Astrofísica e Ciências do Espaço (IA) and with the participation of the the Instituto de Astrofísica de Canarias (IAC), has confirmed the discovery of five exoplanets in the same planetary system, two of them similar to Mercury. The finding provides clues about how these unusual, very high-density planets form. The study is published today in the journal Astronomy & Astrophysics. An international science team has found a system orbiting the cool star HD 23472 with three super-Earths and two super-Mercuries. "We wanted to observe this planetary
Advertised on
Artist’s impression of an ultra-hot Jupiter transiting its star
An international team of astronomers, in which IAC researchers participate, have discovered barium, the heaviest element ever found in an exoplanet atmosphere. It has been discovered at high altitudes in the atmosphere of the exoplanets WASP-76 b and WASP-121 b, two ultra-hot gas giants. The unexpected discovery, made possible by the ESPRESSO instrument at the European Southern Observatory's Very Large Telescope (ESO's VLT), raises questions about what these exotic atmospheres may look like. WASP-76 b and WASP-121 b are no ordinary exoplanets. Both are referred to as ultra-hot Jupiters as
Advertised on
Proxima Centauri Planets
An international team of astronomers, co-led by researchers from the Instituto de Astrofísica de Canarias (IAC), has confirmed the presence of a new planet orbiting Proxima Centauri, the closest star to the Solar System. It is the third planet detected in this star and one of the lowest mass planets ever discovered, with only a quarter of the mass of the Earth. The study, published today in the journal Astronomy & Astrophysics, uses observations made with the ESPRESSO spectrograph on the Very Large Telescope (VLT) at the European Southern Observatory (ESO) in Chile. Proxima Centauri is the
Advertised on