September 5, 2012
Is That A Hot, Habitable Exoplanet In Your Pocket, Or Are You Just Glad To See Me?
Michael Harper for redOrbit.com — Your Universe Online
Good news! The ESO´s HARPS telescope (or High Accuracy Radial Velocity Planet Searcher) team has found a potentially habitable planet around the red dwarf star Gliese 163! This brings the number of known, potentially habitable planets to 6, most of which have been discovered in the past year.
This exoplanet is said to have a minimum mass of 6.9 Earth masses and would take approximately 26 days to completely orbit.
By definition, exoplanets are between 2 and 10 Earth masses and are mostly composed of rock and water. Gliese 163c has a nearby neighbor, Gliese 163b, which is believed to take only 9 days to completely orbit. Another, unconfirmed planet could be orbiting the red dwarf star Gliese 163, but it´s much farther away than 163b and 163c.
According to the international HARPS team, 163c could be much smaller than its neighbors, somewhere around 1.8 to 2.3 Earth radii. With further analysis, the team could better determine what this exoplanet is really made of. Though this planet is potentially habitable, the team has said it receives nearly 40% more light from its star than the Earth does from the sun, making it an incredibly hot place to live.
Abel MÃ©ndez, an Associate Professor of Physics and Astrobiology in the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo and the rest of the HARPS team aren´t yet certain about the atmosphere of this newly discovered exoplanet, however. So far, they suspect that it´s a scaled up version of Earth´s atmosphere, with a surface temperature measuring a very toasty 140 degrees Fahrenheit. By comparison, most living organisms on Earth cannot withstand surface temperatures over 122 degrees Fahrenheit. However, scientists have previously discovered forms of life, known as extremophilic microbial life forms, which thrive in these extremely hot conditions.
Elsewhere in the Gliese 163 zone, MÃ©ndez and his crew have discovered potentially habitable environments on Gliese 581d, Gliese 667Cc and Gliese 581g. They´ve also found habitable plants orbiting a K-Star, called HD 85512 and another orbiting a star similar to our Sun, called Kepler-22b. According to MÃ©ndez, up to 40% of all red dwarf stars could have habitable planets in their orbit.
"Gliese 163c is now part of this statistic, but there should be many more waiting to be discovered,” said MÃ©ndez, speaking to i09.
The discovery of these habitable planets has been heating up in recent months (pardon the pun) as scientists work to build better observatories on Earth´s surface.
“There are more observatories dedicated to these types of searches, and many of them now have the required sensitivity to find these potentially habitable planets,” said MÃ©ndez.
These scientists are looking for planets which closely resemble Earth, though the debate orbiting (again, bad pun) the idea of habitable planets around red dwarf stars has been hotly debated.
Though considered habitable, other environmental aspects about these exoplanets might make life difficult for many organisms. Tides on these planets could make surface temperatures even higher, and stellar winds could erode the planet´s atmosphere very quickly. For comparison´s sake, our solar system doesn´t boast any superterran exoplanets, only smaller planets more or less the size of Earth. Jupiter, for example, is much larger, but is made of gas as opposed to a terrestrial makeup.
The HARPS team has submitted a paper to the scientific journal Astronomy & Astrophysics detailing their findings.