Potentially habitable Earth-like worlds found in our backyard
Astronomers have discovered two potentially habitable worlds orbiting a red dwarf star in our cosmic backyard. Extrasolar planets or “exoplanets” are only 16 light-years away and have masses similar to our planet.
They are located in the ‘habitable zone‘ of its star, GJ 1002, defined as the shell around a star that is neither too hot nor too cold to harbor liquid water, a vital ingredient for life.
“Nature seems bent on showing us that Earth-like planets are very common,” study author Alejandro Suárez Mascareño, from the Instituto de Astrofísica de Canarias (IAC), said in a statement. declaration (opens in a new tab). “With these two we now know of seven in planetary systems very close to the sun.”
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Because liquid water is essential for life to exist, planets in habitable zones are the focus of our search for life in other parts of the world. universe, although the mere fact of being in a habitable zone is not a guarantee of being able to support life. For example, in the solar system both Venus and Mars they are in the habitable zone of the sun, but none of them could currently support life.
Because GJ 1002 is a relatively cool red dwarf, its habitable zone, and these two new exoplanets, are much closer to it than Earth. Sun. The innermost planet, designated GJ 1002b, takes about 10 days to orbit the star, while the outer planet, GJ 1002c, completes one orbit in 21 days.
“GJ 1002 is a red dwarf star, with barely one eighth the mass of the Sun,” said study co-author and IAC researcher Vera María Passegger in the statement. “It is a rather cool and faint star. This means that its habitable zone is very close to the star.”
The proximity of both planets to Earth means they could be excellent targets for astronomers wishing to study the atmospheres of outer Earth-like worlds. the solar system.
The exoplanets were discovered as a result of a collaboration between the ESPRESSO (Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations) instrument of the European Southern Observatory (ESO) installed on the very large telescope (VLT) in the Atacama Desert region of northern Chile, and CARMENES (high-resolution search for Calar Alto M dwarfs with exo-Earths with Échelle optical and near-infrared spectrographs) at the Calar Alto Observatory in Andalusia, southern from Spain.
The two instruments observed the planets’ parent star during two separate periods, CARMENES studied GJ 1002 between 2017 and 2019, while ESPRESSO collected data from the red dwarf between 2019 and 2021.
CARMENES’ sensitivity over a wide range of near-infrared wavelengths makes it ideal for detecting variations in the velocities of stars that may indicate orbiting planets.
“Due to its low temperature, the visible light of GJ 1002 is too weak to measure its speed variations with most spectrographs,” explains Ignasi Ribas, a researcher at the Institute of Space Sciences (ICE-CSIC).
While ESPRESSO and the light-gathering power of the VLT enabled astronomers to make observations of the system that would not have been possible with any other Earth-based telescope, it was the combination of these two powerful instruments that delivered results that alone have struggled to achieve and lead to the discovery of these exoplanets.
“Either of the two groups would have had many difficulties if they had undertaken this work independently,” concludes Suárez Mascareño. “Together we have been able to go much further than we could have done acting independently.”
Astronomers now hope to use the ANDES spectrograph on the extremely large telescope under construction in the atmosphere of GJ 1002c.
The team’s research is published in the journal Astronomy and Astrophysics. (opens in a new tab)
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