Astronomers have observed a second exoplanet in orbit around the nearest star to the sun, the red dwarf called Proxima Centauri.
The still unconfirmed exoplanet is called Proxima c. According to scientists, has a minimum mass that is roughly six times that of Earth, making it a super-Earth. It completes an orbit around its every 1,900 days.
Detection Of Second Proxima Centauri Exoplanet
"We are pleased to show you, for the first time, what is for us a new candidate planet around Proxima that we call Proxima c," announced Mario Damasso of the Astrophysical Observatory of Turin in Italy at the Breakthrough Discuss 2019 held at UC Berkeley.
Damasso and his colleague Fabio Del Sordo of the University of Crete in Greece shared that the discovery of Proxima c happened while the team was reviewing the same expansive multi-year data set that revealed Proxima b in 2016. To find Proxima c, the researchers removed signals coming from Proxima b as well as stellar activity and then added additional measurements from the HARPS spectrograph at the La Silla Observatory in Chile.
"This detection is very challenging," commented Del Soro. "We asked ourselves many times if this is a real planet."
Is Proxima c Habitable?
Del Soro said that due to the nature of the exoplanet's orbit, Proxima c is very unlikely to be habitable. Its star is also a red dwarf that is much smaller and dimmer than the yellow sun of the solar system. The weather in Proxima c is likely frigid and inhospitable.
Proxima b, which completes its orbit around its star after 11 days and is roughly around the size of Earth, would have been a better candidate for life if it were not constantly being bombarded with powerful flares.
Possibility Of Multiple Exoplanets Around Proxima Centauri
Proxima c is still waiting to be confirmed through additional observations by the HARPS instrument.
The European Space Agency's Gaia, which is studying billions of stars in the Milky Way Galaxy, including Proxima Centauri, might reveal the presence of Proxima c. The researchers added that the space satellite might give a "decisive answer" on whether the second exoplanet is real or not by the end of its nominal mission later this year.
Observations of the Atacama Large Millimeter/Submilliter Array, or ALMA, could also confirm the existence of Proxima c and other exoplanets around Proxima Centauri. The facility has already spotted dust lanes in the star system which, scientists theorized, might have been sculpted by orbiting celestial objects.
Del Sordo said that ALMA has also detected a bright object around the area where Proxima c might orbit.
A paper detailing the detection and details of the newly discovered exoplanet is expected to be published in a peer-reviewed journal.