While nearly twice as old as the sun, Barnard's star is relatively inactive and has the fastest apparent motion of any star in the night sky.
Writing in the journal Nature, Guillem Anglada Escudé and colleagues said this newly-discovered world had a mass 3.2 times bigger than the Earth's. So any visible light from the Super-earth is light that is six years old.
While there are different snow lines for each chemical (carbon dioxide doesn't freeze out where water will), the presence of any solids should dramatically change the dynamics of the disks that give rise to planets.
What was going on? van de Kamp's observations were made using a large refracting telescope, and astronomers eventually realised that the telescope's main objective lens had been cleaned and modified several times during the decades of his study. This means that astronomers are getting better at finding and exploring a relatively new kind of planets outside our Solar System. "It has rain and lakes made of methane".More news: Study finds causal link between social media use, depression
The farther a planet is, the less its gravity pulls at the star and the less light it blocks out when it passes between that star and Earth.
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.
The proposed new planet is unlike anything in our own solar system, the researchers say - larger than Earth but smaller than Neptune, and far enough from its dim, red sun that any water on its surface is locked away in ice.
On distance alone, it's estimated that temperatures would be about -150C on the planet's surface.More news: Cricket Australia says country comes before IPL
Despite this particular planet's seeming inhabitability, the reported detection raises hopes that astronomers could get a closeup look at the type of exoplanet considered most likely to have conditions conducive to life. The research pushed the limits of the radial velocity detection technique, which becomes more hard the farther a planet is from its star. The clues came from astrometric signals, which look for deviation in the path of a star from a center line due to the influence of an unseen planet. When an object moves away from us, the light we observe becomes slightly less energetic and redder. That dip, which occurs every 233 days, might be the telltale sign that a planet is in orbit around it.
Using ESO's High Accuracy Radial velocity Planet Searcher (HARPS) and Ultraviolet and Visual Echelle Spectrograph (EVES), the research team found that Barnard's star b orbits about 60 percent closer to its host star than Earth does to the Sun. A clear signal at a period of 233 days arose again and again.
When the next generation of telescopes come online, scientists will be able to characterise the planet's properties. This image shows an artist's impression of the exoplanet viewed from space. "But in the USA, they are also developing WFirst - a small telescope that's also used for cosmology", said Dr Anglada Escudé.
"When we have the image we can then start to do spectroscopy - looking at different wavelengths, in the optical, in the infrared, looking at whether light is absorbed at different colours, meaning there are different things in the atmosphere". "Barnard's star is the "great white whale" of planet hunting".More news: NASCAR legend David Pearson passes away at age 83
Back in the 1960s Peter van de Kamp, a Dutch astronomer based in the United States, reported the discovery of two planets roughly the size of Jupiter orbiting the red dwarf.