St Albans astronomers find habitable planets
PUBLISHED: 12:53 18 March 2014 | UPDATED: 12:54 18 March 2014
Neil Cook, University of Hertfordshire
Astronomers from St Albans are part of an international team which has discovered three new planets classified as habitable super-Earths.
Dr Mikko Tuomi and Prof Hugh Jones, based at the University of Hertfordshire in Hatfield, have joined researchers from the UK and Chile who have been studying the planets.
The three new planets are among eight new planets discovered orbiting nearby red dwarf stars, and the study has shown that virtually all red dwarfs, which make up at least three-quarters of stars in the universe, have planets orbiting them.
Red dwarf stars, which are smaller than the Sun, are red because they burn very little fuel, and are not as hot as other stars.
The local astronomers said the new information was gleaned from analysing data from two high-precision planet surveys carried out by the European Southern Observatory in Chile.
The new planets were discovered around stars between 15 and 80 light years away, and have orbital periods between two weeks and nine years.
That means they orbit their stars at distances ranging from about 0.05 to four times the Earth-Sun distance – 93 million miles.
Dr Tuomi said: “We managed to spot this spectacular haul of planet candidates.”
To find evidence for the existence of the planets, astronomers measured how much a star “wobbles” as it is affected by a planet’s gravity.
As an unseen planet orbits a distant star, the gravitational pull causes the star to move back and forth in space.
This periodic wobble is detected in the star’s light.
Prof Jones said while the find was expected it was, “pleasing to be able to confirm this result with a sample of stars that are among the brightest in their class”.
The team’s paper will be published in monthly notices of the Royal Astronomical Society.