[LINK] On nearby exoplanet HD 219134b

[rfmcdonald]

CBC reports on the confirmation of this close-orbiting rocky world's existence in orbit of a star also known as BD+56 2966 or HR 8832.

"Most of the known planets are hundreds of light-years away. This one is practically a next-door neighbour," said Lars A. Buchhave, an astronomer at the Harvard-Smithsonian Center for Astrophysics, in a statement today. Buchhave is the co-author of a paper about the planet accepted for publication in the journal Astronomy & Astrophysics. The study was led by Ati Motalebi at the Geneva Observatory in Switzerland.

HD 219134b is a super-Earth just 21 light years away. It orbits an orange star that is a little smaller and cooler than our sun, in the constellation Cassiopeia, visible in the night sky near the North Star. It is not in the star's habitable zone – it's too close and too hot for liquid water, or life as we know it, to exist on its surface. Scientists predict that its surface is rocky and partially molten, and might have volcanoes on its surface.

The planet was first discovered by the HARPS-North, the University of Geneva's planet-hunting device on the 3.6-metre Telescopio Nazionale Galileo in the Canary Islands. Data from HARPS-North showed it has a mass 4.5 times that of Earth and sped around its star once every three days.

HARPS-North and its sister instrument HARPS in Chile look for planets by precisely measuring the colour of a star. The gravity of a planet tugs on a star as it orbits, pulling it toward and away from a distant observer on Earth. That movement, in turn, slightly changes the colour of the star as seen from Earth due to the Doppler effect.

Follow-up studies using NASA's Spitzer telescope showed that the new planet has a diameter 1.6 times that of Earth. Based on its mass and diameter, it has the density of a rocky planet.

More, including more on its system, at the site.