Scientists discover super-Earth that could harbour life
London, April 20 (IANS) An international team of astronomers has discovered a so-called "super-Earth" that could contain liquid water, a situation that would make it a very good candidate for harbouring life.
Super-Earth is a rocky, temperate planet orbiting a red dwarf star, Efe news agency reported.
In an article published on Wednesday in Nature magazine, the scientists say that the distant planet, dubbed LHS 1140b, is orbiting an M class red dwarf star a little smaller and dimmer than the Sun but the most common type of star in our galaxy.
The super-Earth and its parent star are located in the constellation Cetus, the Whale, 39 light years from the Sun, thus — relatively speaking — putting it in our galactic "neighbourhood," according to Felipe Murgas, the coauthor of the study and a researcher with Spain’s Canary Islands Institute of Astrophysics.
The study’s main author, Jason Dittmann, with the Harvard-Smithsonian Centre for Astrophysics, said that this is the "most interesting" exoplanet that he’s seen in the last decade.
The new planet was discovered thanks to the MEarth-South telescope network devoted exclusively to seeking out exo-planets.
The MEarth-South instruments enabled scientists to measure the planet’s diameter and, using the HARPS spectrograph at the LaSilla ESO Observatory in Chile, they also were able to measure its mass, density and orbital period.
According to the measurements, LHS 1140b has a diameter 1.4 times that of Earth and a mass 6.6 times that of our own planet.
But more important than that are the climatological conditions, and its orbital distance from its star puts LHS 1140b in the "habitable zone" – thus meaning that the planet’s surface temperature allows water to exist in all three of its states: liquid, solid and as a gas.
Whether there is actually water on the planet or not depends on the composition of its atmosphere and other factors, including the presence of a magnetic field, such as the one Earth has, but the most important thing is for the planet to "fulfil the requirements to have water," which means that it must be in its star’s habitable zone, Murgas said.
Regarding the age of the planet, the authors of the study said that it probably formed in a manner similar to Earth and its star is probably 5 billion years old, about the same age as the Sun, although the age of M-class stars is hard to determine for a variety of factors, the Spanish researcher added.
In the coming decades, LHS 1140b is sure to be investigated much more intensively, an ongoing project for the powerful next-generation telescopes, including the James Webb instrument and the E-ELT device, which will be installed in Chile and — within a few years — will be able to study the system and try to detect its atmosphere, along with other characteristics.