A "super ground" has been discovered on the next single star to our sun, researchers said on Wednesday in a breakthrough that could shine a light on the planet's next planetary neighbors.
Astronomers studied Barnard's Star, a red dwarf just six light years away – practically in our backyard, galactically – and observed the presence of a "frozen, dimly lit world" at least 3.2 times heavier than the Earth.
The planet, today known as Barnard's Star b, is the second closest earth outside the solar system and circles the host star once every 233 days.
"It's important because it's really our next neighbor and we like to meet our neighbors in general," said Ignasi Ribas, from the Institute of Space Studies in Catalonia and the Spanish Space Research Institute.
Although it is relatively close to its parent star, the planet is less than two percent of the energy the Earth comes from the sun, and the team estimates it has an outer temperature of -170 ° C – far too cold to support life as we know.
"It's definitely not in the inhabited zone, no liquid water. If it has some water or gas, it's probably in solid form so that's why we call it frozen," said Ribas.
Dark of a red dwarf
In the command of humanity to map the planets in the night sky, the most historical research has focused on lighter, newer stars, giving more light and increasing the risk of researchers noticing anything that circles them.
But because Barnard Star is a red dwarf, a small and cooling star is probably about twice as old as the sun, it gives relatively little light which makes it difficult to distinguish some bodies in its orbit.
In order to find Barnard's Star b, Ribas and the team studied more than 20 years of observations from seven separate instruments.
They then used a phenomenon called the Doppler effect to track the effects of its gravity pressure on its parent star.
Astronomers can use this technique to measure the velocity of the planet and thus mass.
"We have all worked very hard on this breakthrough," said Guillem Anglada Escude, from London's Queen Mary University, who coincided with the study published in the journal Nature.
& # 39; mini-Neptune & # 39 ;?
The team worked with the European Southern Observatory using astronomical instruments so accurately that they could detect changes in a star speed as low as 3.5 km / h – a gentle walking speed.
It is believed that Barnard's Star tears through space at about 500,000 km / h making it the fastest moving known object in the universe.
Ribas said that although stargazers can predict their size and its orbit with relative accuracy with the Doppler effect, an attempt at this stage is to find out what the new planet looked like "guessing".
"It's kind of in a fuzzy area with respect to its properties. We have seen planets of this mass being rocky, which means that it may look like the earth with a solid surface with possibly some atmosphere or some frozen layers on top," said he.
"Or it might be what we call a mini-Neptune, like a scaled-down version of the gas giants in our solar system."
It can be cold, rude and all but invisible, but the new planet has one thing that goes for it: it's very close.
The only known exoplanet closer to the Earth was discovered in 2016 and revolves around one of a cluster of stars in the Alpha Centauri system, just over four light years away.
"There are not so many stars in our immediate vicinity. The investment to find them is expensive," said Ribas.
"It's really close and because if you've jumped – as I do – eventually seeing these planets to study them in detail, we have to start with the immediate ones. It can potentially lead to other discoveries."
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