Published: Fri, November 16, 2018
Sci-tech | By April Francis

Super-Earth Discovered Orbiting Closest Single Star to the Sun

Super-Earth Discovered Orbiting Closest Single Star to the Sun

The new exoplanet (if it exists) is an icy world just over three times the mass of Earth, and has only been uncovered as a result of an exhaustive search by teams across the globe.

Less than six light-years away from our Sun, the potential planet orbits Barnard's Star, a well-studied low-mass red dwarf star in the Ophiuchus constellation.

The discovery is reported in the journal Nature. That's hard to do because, viewed from Earth, the planet is close to the star and swamped by its glare. It's probably very rich in volatiles like water, hydrogen, carbon dioxide - things like this.

"This new discovery offers exciting prospects to learn more about the galaxy's diversity of planetary systems, starting with our own solar system's near neighbours". "It has rain and lakes made of methane". "The precision of new measurements continues to improve, opening the doors to new parameters of space, such as super-Earth planets in cool orbits like Barnard's Star b".

During the course of their study, Smithsonian notes, researchers found faint evidence of another planet, which would be Barnard's Star c.

In the absence of an atmosphere, the planet's temperature is likely to be about -150 ºC, which makes it unlikely that the planet can support liquid water on its surface.

However, if the planet has a substantial atmosphere the temperature could be higher and conditions potentially more hospitable.

Part of the challenge of finding the planet comes from the method that astronomers used: radial velocity (RV). The technique can detect "wobbles" in a star caused by the gravitational pull of an orbiting planet. Astronomers have been measuring minuscule characteristics of the star for decades, searching for signs of orbiting planets, and over the years, hints of a possible world tugging on the star have been gleaned here and there-but nothing was ever considered conclusive.

A planet has been detected orbiting Barnard's Star, a mere 6 light-years away. The European Space Agency's Gaia mission could eventually shed light on this question, since the spacecraft is created to precisely track the movements of stars.

One of them was the new state-of-the-art planet-hunting instrument Carmenes at the Calar Alto Observatory in Spain.

This is the first time that a planet this small and distant has been detected using the radial velocity technique, which Butler helped pioneer. "Certainly, even with our current technology, we could launch unmanned probes to send back pictures of this planet".

A clear signal at a period of 233 days arose again in a re-analysis of all the measurements combined. Hundreds of exoplanets have been found by looking for periodic Doppler shifts in the frequency of starlight. Meanwhile, the focus has shifted to nearby stars, as astronomers have started building a catalog of targets for the next generation of telescopes. "It was a community effort", Ribas says.

A spectrograph is an instrument that separates light by its wavelengths and records the data. Barnard's Star has a long history with astronomers making dubious exoplanet claims, and the researchers took great care to avoid repeating history.

In the 1930s, Dutch-American astronomer Peter van de Kamp began a quest to study Barnard's star that lasted for most of his 93 years.

The European Space Agency's Gaia Space Observatory may be able to make detections that would further confirm the presence of a planet around Barnard's Star, he said, but those data aren't expected to be released until the 2020s.

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