There’s an alien world located 4.2 light-years from Earth in the constellation Proxima Centauri. Its name is Proxima b, and it is considered the closest potentially habitable world to Earth. Part of a triple star system, Proxima b, could be the first planet a manmade spacecraft is set to visit in the future.
Although one of th closest and most interesting planets out there (mostly due to its proximity to Earth), we didn’t really know much about it. Does it support life? Does it have liquid water? What’s its orbital inclination? What’s its mass? And more importantly, does it even exist?
Now, researchers led by the Canary Islands Astrophysics Institute (IAC) have gathered substantial evidence that confirms the presence of Proxima B, with unprecedented precision.
Proxima b’s existence was confirmed using radial velocity measurements made with the new ESPRESSO (not the Italian drink, of course) instrument, the most accurate spectrograph built to date, installed in the Very Large Telescope (VLT), located at the Cerro Paranal Observatory in Chile and belonging to the European Southern Observatory (ESO).
The study, led by IAC researcher Alejandro Suárez Mascareño, presents strong evidence of the presence of the planet Proxima b, discovered four years ago orbiting the closest star to the Sun, Proxima Centauri.
A team led by researcher Guillem Anglada-Escudé measured a disturbance in the star’s radial velocity of just over 1 meter per second, near the limit of the precision of the instruments of the moment.
ESPRESSO has obtained radial velocity measurements on the Proxima Centauri star with an accuracy of 30 cm / s, four times better than those obtained with HARPS, the instrument used for the discovery of the exoplanet. Combining this precision with the number of photons that the VLT, in which it is installed, can collect, opens the door to discovering the population of terrestrial planets (even mass much less than Earth) in the stars of the solar neighborhood.
“ESPRESSO has shown that it can do better than any previous spectrograph,” explained Alejandro Suárez Mascareño, the first author of the paper.
“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.”
Since Proxima b is one of the most interesting exoplanets out there, and due to its close priority to Earth, it was imperative to confirm its existence, scientists have revealed.
“It is one of the most interesting planets known in the solar neighborhood. 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,” revealed co-author of the study Jonay González Hernández.