Super-earth confirmed, first of many? February 3, 2009Posted by Sarah in science.
Tags: astronomy, CoRoT, esa, eso, exoplanet, kepler, texas
Today with much to-do and under heavy embargoes, scientists have announced the discovery of an extrasolar planet with a mass diameter of just 1.7 times that of the Earth. That’s very very small. With a mass of It whizzes around its host star, Exo-7, in around 20 hours and with a temperature of over 1,000 degrees, is incredibly hot. Using data from the satellite CoRoT (Convection Rotation and planetray Transits), the
German-led French-led team of scientists detected the minute dip in the light coming from the host star from the planet passing in front of it. The discovery was confirmed with observations at a number of ground-based observatories, including VLT, the Canada-France-Hawaii telescope, McDonald Observatory.
In case you hadn’t noticed: exoplanet news is coming hard and fast. Every year since 1995, when Mayor & Queloz reported the discovery of 51 Peg b, has seen a number of “major breakthroughs” (see here, here, and many more) in the detection and characterisation of planets around other stars in our Galaxy. Scientists have pushed the boundaries of our knowledge to a massive extent, and the rapid progress is just fantastic. But brace yourself for more.
While the CoRoT Exo-7b discovery is clearly an exciting result and I certainly wouldn’t want to detract from the team’s accomplishments, let’s keep this in perspective. After all, CoRoT was designed specifically to detect planetary companions or seismic-like activity below the stellar surface. To do this, it stares at stars and records their light intensity to a high precision for an unprecedented amount of time. Since its launch in December 2006 and first light early in 2007, it has measured many thousands of stellar light curves; over the mission lifetime, it will look at over 120,000 stars!
The CoRoT mission was planned from the late 90s, soon after the first exoplanet discovery, and is one of the first major exoplanet surveys of its kind. The satellite is working a treat, so the number of known exoplanets will go through the roof in coming years. And NASA’s planet hunting Kepler mission is set for launch in March of this year.
In fact, the rate of discovery at this stage is most likely limited by how quickly people can actually examine the data.
Like with stars and galaxies, which we now know to come in every imagineable size, colour and flavour, the parameter space of the planets’ physical properties is likely to increase by orders of magnitude as well. This raises a bit of a PR question, as announcing every single one of these outliers could quickly become very boring indeed. I hope the media folks at ESA and CNRS have given this some thought and devised a strategy to give proper credit to scientists’ and engineers’ accomplishments with the CoRoT mission without causing major media (and public) exoplanet fatigue.
I presume the results were presented at the CoRoT science symposium that is taking place this week in Paris. Read the press release from Paris-Meudon Observatory here, from ESA here. The paper by Léger et al. will soon be submitted to a special edition of A&A dedicated to CoRoT science.
Image credit: CNRS