Researchers confirm existence of Earth-like planet in habitable zone

Santa Cruz de Tenerife, Spain, May 26 (efe-epa).- Proxima b, an exoplanet that was discovered four years ago, orbits the star closest to the Sun making it an earth-like planet located in a habitable area, an international team of experts announced on Tuesday.

When the star was discovered four years ago, experts identified it as a potential candidate exoplanet with a similar mass to the Earth and within the habitability zone of Proxima Centauri star, something the team has confirmed with more precise measurements.

Planets that orbit in a star’s habitable zone, where conditions are suitable for the presence of liquid water, a necessity for life as we know it, are of particular interest to space explorers.

Using Espresso, the team was able to take radial velocity measurements with an accuracy of 30 cm per second, four times the precision than those obtained with Harps, the instrument used for the planet’s discovery.

The investigation was carried out by researchers from the Canary Islands Institute of Astrophysics (IAC) and the European Southern Observatory (ESO) confirmed the presence of the exoplanet using the Espresso spectrograph on the Very Large Telescope (VLT) in Chile.

“Espresso has shown that it can do better than any previous spectrograph,” Alejandro Suárez Mascareño, the first author of the paper said.

“A new scenario is opening up. Until now we have been restricted to the discovery of planets with masses several times that of the Earth, or at the limit with a mass about one Earth mass, orbiting cool stars. With Espresso that limitation is gone”.

The highly precise spectrograph was crafted through an international consortium that included the University of Geneva (Switzerland), Institute of Astrophysics and Space Sciences (Portugal), National Institute of Astrophysics (INAF, Italy), Institute of Space Sciences (Portugal), Center for Astrobiology in Spain and ESO.

The new observations have refined knowledge of the planet’s physical parameters.

According to Jonay González Hernández, an IAC researcher and a coauthor of the publication: “It was an important task to confirm Proxima b.”

“It is one of the most interesting planets known in the solar neighbourhood. Its mass, similar to the Earth’s, the possibility that it could host life, and its proximity, make into one of the ideal candidates to search for biomarkers using the next generation of telescopes, such as the Hires spectrograph for the future 39 m ELT, in whose construction the IAC is participating”.

During the confirmation of Proxima b, the team found evidence of a second signal in the data the origin of which has not been identified.

If the signal is confirmed to be another planet, its mass would be less than a third of that of the Earth’s, Rafael Rebolo, director of the IAC added.

The search for exoplanets has intensified in recent years and is tied to a quest to find extraterrestrial life.

When researchers find a candidate exoplanet an assessment of the body’s habitability is undertaken. Planetary habitability is the study of a vast range of options beyond being within a star’s habitable zone. It determines a planet’s ability to host life.EFE-EPA

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