Jul 19, 2011 09:01 GMT  ·  By
A rendering of the silhouette of 55 Cancri e transiting its parent star, compared to the Earth and Jupiter transiting our Sun
   A rendering of the silhouette of 55 Cancri e transiting its parent star, compared to the Earth and Jupiter transiting our Sun

During a recent investigation, scientists were able to observe an eclipse taking place in a star system located just 40 light-years away. This is practically in our backyard in astronomical terms, and the team behind the work believes that this is what allowed them to discover a super-Earth-class planet.

The study was led by astronomers at the Massachusetts Institute of Technology (MIT), in Cambridge. By observing the exoplanetary eclipse, they were able to infer some of the key properties of the extrasolar planet that was causing the effect.

According to early studies, it would appear that the super-Earth exoplanet – which has been dubbed 55 Cancri e – is about 9 times heavier than our planet, and nearly twice its size. As such, a perfect fit into its class, the team says.

It is currently believed that the object is made from rocky materials and minerals, just like our home world is. At the same time, the celestial body may also contain lighter chemicals as well, including water and hydrogen gas.

However, finding liquid water or breathable air on 55 Cancri e is out of the question, the MIT team says. The surface of the exoplanet is heated to nearly 2,700 degrees Celsius, which means that any water that may have been on the surface at one point has long since evaporated.

“Everything we do in astronomy is starving for more light. The more light a star gives you, the more chances you have of learning something interesting […] and everyone’s been waiting for a system like this that you can study in great detail,” says Josh Winn.

The expert is the MIT Class of 1942 Career Development assistant professor of physics. He says that exobiologists would do better to search for life elsewhere in the Universe. On the other hand, astronomers may have a field day with this star.

When viewed under good conditions 55 Cancri appears to be about 100 times brighter than any other known star with an eclipsing planet around it. The MIT team collected data of the object using the Canadian Microvariability and Oscillations of Stars space telescope (MOST).

“If [a planet] is just hugging the star, there’s a greater chance of an eclipse, versus if the planet is really far out, in which case you have to be luckier to see it right in front of the star,” Winn says.

But this is also the reason why the exoplanet is so hot. In all likelihood, it is tidally locked to its parent star, which means that it always keeps the same face pointed towards it. In our solar system, the Moon and the planet Mercury are goon analogues of tidally locked objects.

“It’s still going to be hard to learn everything about this planet. But at least we have what might be the best system in the sky to study it,” Winn concludes.