The universe is infinite, and as technology catches up with our curiosity, we’ve been able to explore more of it.

Astronomers have now discovered an exoplanet more than three times the mass of Earth, orbiting a star that’s only six light-years away.

All of the planets in our (Earth’s) solar system orbit the sun. An exoplanet is a planet that orbits around another star.

This particular planet is orbiting Barnard’s star, the closest solitary star to our sun, making it the second closest known exoplanet to us – the first being the one found orbiting in the three-star Proxima Centauri system.

CNN call it a “frozen super-Earth”:

The exoplanet was found after stitching together 20 years of data, including 771 individual measurements, from seven instruments.

…”The biggest ‘kick’ about this discovery is the host star,” Paul Butler, study co-author and astronomer at the Carnegie Institution for Science, wrote in an email. “Barnard’s star is the ‘great white whale’ of planet hunting.”

The planet, known as Barnard’s star b, is probably dimly lit by its star and slightly colder than Saturn. The researchers believe that it is an icy desert with no liquid water, a hostile environment where the average surface temperature is around minus-274 degrees Fahrenheit.

Artists have rendered the below images:

The red dwarf emits only around 0,4% of our sun’s radiance, which means that the planet only receives around 2% of the intensity that the Earth receives from the sun.

This is because Barnard’s star, named after the American astronomer Edward Emerson Barnard, is in the class of M dwarf stars, cooler and less massive than our sun.

Here’s another cool fact: it’s also an old star that predates our own solar system.

This is the first time that a planet this small and distant has been detected using the radial velocity technique, which Butler helped pioneer.

The planet is about the same orbital distance from its star as Mercury is from our sun, making a full pass around the star every 233 days. This places it in the “snow line” of the star, where it’s cold enough for water to freeze into solid ice. This region in a planetary system is where the building blocks of planets are thought to form, collecting material to become cores. As they migrate closer to their host stars, gathering more material, they become planets.

This discovery showcases the power of the radial velocity technique for detecting small planets.

These methods haven’t always been available to astronomers searching for exoplanets. For most of the past hundred years, the only way was the astrometric technique, in which astronomers look for the host star to wobble relative to background stars, Butler said. It worked only for the nearest stars and was achieved by taking photographs of the star and measuring its positions in relation to one another.

Given how close the exoplanet is to our solar systems, future missions and telescopes should be able to provide more insight into the composition of the surface, and the atmosphere of the planet.

Space, hey – the final frontier.

[source:cnn]