LONDON: A new ‘secret’ planetary system that includes three super-Earths and one outer giant planet has been discovered by astronomers at a distance of just 21 light years from Earth.
Named HD219134, the system in the constellation Cassiopeia hosts one outer giant planet and three inner superEarths, one of which transits in front of the star and has a density similar to the Earth’s. It is by far the closest transiting planet known today, researchers said.HARPS-N, designed and built by an international consortium and installed at the Telescopio Nazionale Galileo in Spain’s La Palma Island unveiled the exceptional planetary system around HD219134.
The star, a 5th magnitude K dwarf, slightly colder and less massive than our Sun, is so bright that we can follow it with a naked eye from dark skies, next to one leg of the W-shape Cassiopeia constellation, all year round in our boreal hemisphere, researchers said.
The cortege of planets composed of three mostly rocky super-Earths and an outer giant planet, a configu ration reminiscent of our own Solar System, they said. “When the first HARPS-N ra dial-velocity measurement indicated the presence of a 3 day planet around HD219134 we asked NASA for Spitzer space telescope to check for a potential transit of the plan et in front of the star, a mini eclipse, that would allow us to measure the size of the planet,” said Ati Motalebi, astronomer at University of Geneva and lead author of the paper describing the discovery.