Every Red Dwarf Hosts an Alien Planet, Study Says

Nearly three quarters of the stars in the Universe, which are Red Dwarfs, have planet revolving around them.

A team of international astronomers discovered eight new planets orbiting around red dwarf stars out of which three planets were classified as habitable-zone super-Earths. This means liquid water might have existed there making them potential candidates to sustain life. The researchers also suggest that such life sustaining Earth like planets revolve around at least a quarter of the red dwarfs in the cosmic world.

These stars have been identified 15-80 light years away and their orbital period varies from two weeks to nine years, suggesting they revolve their stars at a distance of 0.05 to 4 times the distance of the Earth from the Sun i.e. 149 million kilometers.

The discovery was made after examining data retrieved from the two high precision planet surveys namely HARPS and UVES.

Both the planet surveys, HAPRS -High Accuracy Radial Velocity Planet Searcher and UVES-Ultraviolet and Visual Echelle Spectrograph, are being operated from Chile by the European Southern Observatory. Combining the data of the two planet surveys, the researchers successfully traced the weak signals that were not visible in the data.

"We were looking at the data from UVES alone, and noticed some variability that could not be explained by random noise. By combining those with data from HARPS, we managed to spot this spectacular haul of planet candidates. We are clearly probing a highly abundant population of low-mass planets, and can readily expect to find many more in the near future - even around the very closest stars to the Sun," said Dr Mikko Tuomi from University of Hertfordshire's Centre for Astrophysics Research, in a news release.

Detecting the New Planets:

To trace the existence of these planets, the astronomers initially measured the rate at which the star wobbles in the Universe under the effect of the planet's gravity. The gravity of the orbiting planet causes a to and fro motion for the star in space. It is in the star's light that this periodic front and back motion is detected.

An array of novel techniques used to detect the planetary signals include Baye's rule of conditional probabilities, this enables the astronomers to determine the chances of the star having orbiting planets. Combining this with a technique, the researchers filtered the extra noise in the measurement and came up with their finding.

Professor Hugh Jones, also from the University of Hertfordshire, commented: "This result is somewhat expected in the sense that studies of distant red dwarfs with the Kepler mission indicate a significant population of small radius planets. So it is pleasing to be able to confirm this result with a sample of stars that are among the brightest in their class."

The finding will be documented in the Monthly Notice of the Royal Astronomical Society.