Sunday, 20 May, 2018

Pair of super-Earths found orbiting star K2-18

HARPS Instrument Pair of super-Earths found orbiting star K2-18
Theresa Hayes | 07 December, 2017, 07:15

A recently discovered planet named Super Earth unveiling that it could hold numerous critical components of alien life. K2-18b, scientists say, could be in an excellent location for alien life to emerge-having flawless conditions for surface water, a fundamental ingredient for life, to exist.

The study was made possible thanks to data obtained from the ESO's 3.6 m telescope at the La Silla Observatory in a remote region of Chile.

Located 111 million light years away, the planet known as K2-18b has been described as a potential "Super-Earth" - a large rocky planet capable of supporting life. It was first identified in 2015. Sitting within the habitable zone of the star, astronomers have been investigating whether or not it could support life.

At present, the researchers have been able to narrow down K2-18b's makeup to just two possibilities.

Using the fiber-optic HARPS technology, the astronomers watched the changing position and speed of stars. "Once all the boxes were checked it sunk in that, wow, this actually is a planet", said Ryan Cloutier, who had the target of finding at least one new exoplanet during the course of his Ph.D. That is, it's made of mostly solid, not gas.

By collecting so-called "radial velocity" data on K2-18, the scientists were able to estimate the size of K2-18b. Scientists, aside from two regular signals that they received every 39 days from the star's rotation and every 33 days from the planet's orbit, discovered a third signal which they received every nine days, which was the first indication that there might be another planet close to K2-18b. "And from how far away it is from the star, it gives you an idea of how hot the surface of this planet might be", Cloutier told CTV News Channel on Tuesday.

Lead researcher Ryan Cloutier, astronomy and astrophysics PhD candidate with the University of Toronto, said it's too early for the team to know whether or not the planet hosts life.

"But with the James Webb Space Telescope (JWST), we can probe the atmosphere and see whether it has an extensive atmosphere or it is a planet covered in water", he said. According to study authors, the discovery sheds important light on the prevalence of multi-planet systems around dwarf stars like K2-18.

Study co-author Professor René Doyon, also from the University of Montreal, added: "There's a lot of demand to use this telescope, so you have to be meticulous in choosing which exoplanets to look at". James Webb Space Telescope is created to observe some of the most distant events and object in the cosmos in the most exceptional clarity.

Using a machine-learning approach the researchers were able to determine that K2-18b was either a rocky planet with a bigger gaseous atmosphere than Earth or a water planet with a thick layer of ice on top of it.