Super-Earth Exoplanet Found Orbiting Barnard's Star | Astronomy

Jo Lloyd
November 17, 2018

Not many instruments are capable of noticing that a stars velocity has slowed by the walking pace of a human - a tiny 3.5 kilometres an hour - but ESO's planet-hunting HARPS instrument is one of them and its unprecedented accuracy helped the team to spot the super-cold, super-Earth.

A potentially rocky super-Earth orbits one of our closest stellar neighbors, Barnard's star, only 6 light-years away.

It orbits Barnard's star, which sits "just" six light-years away.

Unlike many other red dwarfs, Barnard's Star is relatively inactive and not so likely to blast nearby planets with radiation that would not give life a chance.

There are a lot of red dwarf stars reportedly producing several flares and spasms that look like an orbiting planet. This places it in the "snow line" of the star, where it's cold enough for water to freeze into solid ice. The exoplanet orbits Barnard's star, the lonely star closest to our sun. This star was discovered to host a frozen super-Earth exoplanet.

The newfound globe is called Barnard's star b, or GJ 699 b, and is a little more than three times the mass of Earth with a surface temperature of -150 Celsius (-238 Fahrenheit). These include NASA's Wide Field Infrared Survey Telescope (WFIRST) and the European Space Agency's Gaia astrometry mission. It is smaller and older than our Sun and among the least-active known red dwarfs.

It's thought that Barnard's Star is tearing through space at around 500,000 km/h, making it the fastest-moving known object in the universe.

The physical motion of the star is far too small to detect.

This technique detects wobbles in a star which are likely to be caused by the gravitational pull of an orbiting planet. This method takes advantage of that fact that not only does a star's gravity obviously influence the planet orbiting it, but the planet's gravity also affects the star in turn. That's faint. Even though it's close to us, it's so dim you'd need good binoculars or a small telescope to see it at all! "We followed Barnard's star for 16 long years at Keck, amassing some 260 radial velocities of Barnard's star by 2013", Vogt said. But as Barnard's star is said to be very calm and behave based on observations, Ribas and his team are confident that what they saw is a real planet.

Graphic representation of the relative distances to the nearest stars from the Sun.

The closest stars to the Sun. This image shows an artist's impression of the exoplanet viewed from space. "[The candidate] is very strong in terms of the statistical significance". "The combination of all data led to a total of 771 measurements - a huge amount of information!"

Barnard's Star b appears to have an orbital period of 233 days. "However, we must remain cautious and collect more data to nail the case in the future", Ribas said.

Barnard's Star formed way before our solar system existed. Knowing the star's mass, we can then determine the planet's mass of 3.2 times the Earth's (this is found by how much the planet tugs on the star).

Since the 1960s, scientists and exoplanet hunters have searched for evidence of planets orbiting one particular star. This means that astronomers are getting better at finding these kinds of planets outside our solar system. "Hopefully we got it right this time", said Guillem Anglada Escude from Queen Mary's School of Physics and Astronomy.

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