Astronomers have discovered evidence of a third planet orbiting Proxima Centauri, our sun's closest star neighbor. However, experts say this exoplanet is too hot to be inhabited.
A light-year is the distance light travels in a vacuum in one year, approximately 5.88 trillion miles (9.46 trillion kilometers).
The rocky object is one of the lightest exoplanets yet discovered, with a mass of around a quarter that of Earth.
The tiny, faint red dwarf star has an eighth of the mass of the sun and already has one verified Earth-size planet and a possible second, further away from the planet candidate.
Researchers detailed their study, "A Candidate Short-Period Sub-Earth Orbiting Proxima Centauri," in the journal Astronomy & Astrophysics.
The study lead author is João Faria, a researcher at the Instituto de Astrofísica e Ciências do Espaço in Portugal.
This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image to the upper-right of Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.
Proxima D: Potential Requirements for Life
With the identification of Proxima d, the third probable exoplanet, Proxima Centauri, now has the potential to host a diverse range of planets. However, the newly found planet is less than half the size of Earth and probably too hot to be inhabited.
NBC News said the new planet is so near to its star - roughly a tenth of the distance between the sun and Mercury - that an orbit around it takes only five days.
As the moon is to Earth, it's also expected to be "tidally locked," with one face always pointed toward Proxima Centauri.
This might result in temperature extremes and reduce the chances of the planet having a stable atmosphere.
Scientists are ecstatic about the finding despite the potentially hazardous conditions on the new planet.
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Proxima b, the first planet discovered in the system, was verified in 2020. It's roughly the size of Earth and takes 11 days to orbit the star.
It's in the habitable zone, or the distance from a star where the circumstances are correct for liquid water to exist on the planet's surface, which is one of the main elements for life as we know it.
Proxima d, which orbits the star in about five years, is too near for the star to be in the habitable zone. Meanwhile, Proxima c, which orbits the star in about five years, is too far away.
About Proxima Centauri
Proxima Centauri might be home to a diverse range of planets.
While experts don't now have the technology to go to Proxima Centauri in any type of realistic time frame, The Verge said these planets might be among the first astronauts would visit if we ever do.
For the time being, their relative vicinity to Earth makes them ideal candidates for further investigation and monitoring. According to astronomers, they might aid experts in their ongoing search to learn how planets develop around distant stars.
According to Faria, the Proxima system might be "packed with planets."
It's also a watershed moment in the way scientists hunt for planets around distant stars, he added, which might lead to the finding of even more soon.
Other measurements will be needed to confirm the existence of the new planet, but Faria and his co-authors claim to have found it in minute changes in Proxima's brightness - "wobbles" created by the planet's gravity.
The first planet discovered orbiting Proxima in 2016 and a second planet discovered in 2019 were discovered using similar procedures.
However, the most recent search employed light collected by a new spectrograph at the Very Large Telescope on a hilltop in northern Chile's Atacama Desert - a more sensitive device than previously used.
RELATED ARTICLE: European Southern Observatory Finds New Exoplanet Orbiting Proxima Centauri; Is Proxima d Lighter Than Earth?
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