Researchers Discover Three “Super-Earths”
European researchers discovered what looked to be three ‘super-Earths’ orbiting around a star and two other solar systems that contained small planets. They believe that these large Earth-like planets are more common then we think.
“Does every single star harbor planets and, if yes, how many?” asked Michel Mayor of Switzerland’s Geneva Observatory. “We may not yet know the answer but we are making huge progress towards it,” Mayor said in a statement.
The three planets are orbiting a star that is only a little bit smaller then the Sun. They are 42 light years away and facing the southern Pintor and Doradus constellations. (Light year is the distance that light can travel in one year when traveling at a speed of 186,000 miles a second.)
They orbit their star at extremely rapid speeds — one whizzing around in just four days, compared with Earth’s 365 days, one taking 10 days and the slowest taking 20 days. Mayor and colleagues used the High Accuracy Radial velocity Planet Searcher or HARPS, a telescope at La Silla observatory in Chile, to find the planets.
Over 270 of these ‘exoplanets’ have been discovered so far. Most of these planets are the size of Jupiter or Saturn – but there are also smaller ones that are the size of Earth – which are much more difficult to find.
None can be imaged directly at such distances but can be spotted indirectly using radio waves or, in the case of HARPS, spectrographic measurements. As a planet orbits, it makes the star wobble very slightly and this can be measured.
“With the advent of much more precise instruments such as the HARPS spectrograph … we can now discover smaller planets, with masses between 2 and 10 times the Earth’s mass,” said Stephane Udry, who also worked on the study.
The team also said they found a planet 7.5 times the mass of Earth orbiting the star HD 181433 in 9.5
“Clearly these planets are only the tip of the iceberg,” said Mayor. “The analysis of all the stars studied with HARPS shows that about one third of all solar-like stars have either super-Earth or Neptune-like planets with orbital periods shorter than 50 days.”