Astronomy Now Home
Home Magazine Resources Store

On Sale Now!

The October 2014 issue of Astronomy Now is on sale! Order direct from our store (free 1st class post & to UK addresses). Astronomy Now is the only astronomy magazine specially designed to be read on tablets and phones. Download the app from Google Play Store or the Apple App Store.

Top Stories

Earthshine used to test life detection method
...By imagining the Earth as an exoplanet, scientists observing our planet's reflected light on the Moon with ESO's Very Large Telescope have demonstrated a way to detect life on other worlds...

Solid buckyballs discovered in space
...Astronomers using NASA’s Spitzer Space Telescope have detected a particular type of molecule, given the nickname “buckyball”, in a solid form for the first time...

Steamy water-world gets the Hubble treatment
...Hubble Space Telescope observations of a 7 Earth-mass planet find an unusual water-rich world swathed in a thick, steamy atmosphere...

Sizing up a
temperate exoplanet

Posted: 17 March 2010

Bookmark and Share

Combining observations from the CoRoT satellite and ground-based ESO HARPS instrument, astronomers have a discovered a 'standard' exoplanet that is set to become the Rosetta stone of exoplanet research.

“This is a normal, temperate exoplanet just like dozens we already know, but this is the first whose properties we can study in depth,” says exoplanet hunter Claire Moutou. “It is bound to become a Rosetta stone in exoplanet research.”

Artist's impression of CoRoT-9b transiting its host star. Image: ESO.

Initially discovered by the French space agency operated CoRoT (Convection, Rotation and Transits) space telescope in 2008 using the transit method, whereby a tiny amount of the star's light is blocked out as the planet moves across the disc of the star, confirmation of the object's exoplanet mass and density was provided by the HARPS instrument attached to the 3.6 metre telescope at La Silla in Chile.

Like many other of the 400 exoplanets discovered to date CoRoT-9b has a similar size to Jupiter, but it stands out from the crowd in that its distance from its host star is about ten times larger than that of any planet previously discovered by the transit method, placing it at a similar distance as Mercury is from our Sun.

“Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium,” says team member Tristan Guillot, “and it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures.”

The planet passes in front of its host star once every 95 days and takes eight hours to make the transit, offering astronomers the chance to glean bountiful information on the nature of the planet. They team report that CoRoT-9b has an unusually temperate climate, with the temperature of its gassy surface ranging from -20 degrees Celsius to 160 degrees, and with minimal day-to-night variations.

“Our analysis has provided more information on Corot-9b than for other exoplanets of the same type,” says Didier Queloz. “It may open up a new field of research to understand the atmospheres of moderate- and low-temperature planets, and in particular a completely new window in our understanding of low-temperature chemistry.”

The results of the discovery are published in today's edition of the journal Nature.

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.

Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.

3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!


© 2014 Pole Star Publications Ltd.