Astronomers discover distant planet using off-the-shelf tech
By Jenna Meade
December 29, 2009
Astronomers have proved that even the most basic technology can reveal significant developments in the heavens above. Using a simple ground-based telescope, a team from the Harvard-Smithsonian Center for Astrophysics (CfA) located a “super-Earth” orbiting a red dwarf star only 40 light-years away from Earth.
A super-Earth is a planet sized between one and ten times the mass of the Earth and the new discovery, named GJ1214b, measures up at about 6.5 times the size. Its radius is about 2.7 times the size of Earth - making it, along with the distinctly unwelcoming CoRoT-7b, one of the smallest transiting exoplanets discovered so far.
GJ1214, the planet’s host star, is about one-fifth the size of the sun with a luminosity only three-thousandths as bright as the Sun. It's a short year on GJ1214b - the planet orbits its star once every 38 hours at a distance of only 1.3 million miles.
The super-Earth has an estimated temperature of approximately 400 degrees Farenheit but surprisingly astronomers predict that it is composed of about three-fourths water and other ices, and only one-fourth rock.
"Despite its hot temperature, this appears to be a waterworld," said Zachory Berta, a graduate student at the Harvard-Smithsonian Center for Astrophysics (CfA) who first spotted the hint of the planet among the data. "It is much smaller, cooler, and more Earthlike than any other known exoplanet."
How so? According to Berta the planet's water should be in the form of exotic materials like Ice VII (seven) - a crystalline form of water that exists at pressures greater than 20,000 times Earth's sea-level atmosphere.
The planet is predicted to have been around for multiple billion years and the team is concerned that much of the original atmosphere may have been lost because the star’s heat is gradually boiling it off. Amazingly, the planet was was spotted using readily available tech - an array of small eight identical 16-inch ground-based telescope and a CCD camera called the MEarth (pronounced "mirth") Project.
"Since we found the super-earth using a small ground-based telescope, this means that anyone else with a similar telescope and a good CCD camera can detect it too. Students around the world can now study this super-earth!" said David Charbonneau of CfA, lead author and head of the MEarth project.
The team hopes to delve deeper into the planet to discover its characteristics using instruments like NASA’s Hubble Space Telescope.
The discovery is being published in the December 17 issue of the journal Nature.