A HABITABLE PLANET NAMED GLIESE 163c

 Artistic picture of Gliese GLIESE 163c

Dubbed Gliese 163c, the planet – with a mass of 6.9 times that of Earth and an orbital period of 26 days – orbits a red dwarf star 49 light years away in the Dorado constellation.
The team has also detected a larger planet, Gliese 163b, orbiting the star much closer with 9 day period. An additional third, but unconfirmed planet, might be orbiting the star much farther away.
The new exoplanets are described in a paper submitted to the journal Astronomy & Astrophysics.
Gliese 163c could have a size between 1.8 to 2.4 Earth radii, depending if it is composed mostly of rock or water, respectively. It receives on average 40 % more light from its parent star than Earth from the Sun, making it hotter.

“We don’t know the properties of the atmosphere of Gliese 163c but, if we assume that it is a scaled up version of Earth’s atmosphere, then its surface temperature might be around 60°C,” the researchers said.
The potential for habitability of planets around red dwarf stars has been an issue of much debate. Tidal effects on planets around these stars might cause extra surface heating or even tidal locking. Also, these stars are more active and their stellar wind might erode planetary atmospheres much faster. These factors might preclude the potential for life on smaller planets but not for planets with thicker atmospheres, something expected for superterran planets.
“NASA’s Kepler Mission has detected about 27 potential habitable exoplanets candidates out of their over 2,300 exoplanets that are waiting to be confirmed. Some of these bodies seem very Earth-like. Unfortunately, they are much farther away from us than Gliese 163 and it will be nearly impossible to determine if they are really habitable worlds by future observations.”
“However, the statistical analysis of Kepler data suggests that these planets are very common in the galaxy. Therefore, many more Earth-like worlds are waiting to be discovered in our solar neighborhood too, such as Gliese 163c.”


The orange light is the red dwarf of Gliese 163c

Despite the positive hopes for Gliese 163c, Bonfils also cautioned that there are also several possible uninhabitable conditions as well.  Bonfils, along with an international team of fellow astronomers, studied almost 400 red dwarf stars using the High Accuracy Radial Velocity Planet Searcher (HARPS) spectograph, located  on the 3.6-meter telescope at the European Southern Observatory’s La Silla Observatory in Chile
The super Earth was one of two planets they found orbiting the star Gliese 163, which is located about 50 light-years away from Earth in the Dorado constellation. While they discovered evidence of a third planet around the star, they cannot conform it yet.
Gliese 163c is about seven times the mass of Earth and has the potential to either be a rocky planet or a dwarfed gas giant. Bonfils stated:

“We do not know for sure that it is a terrestrial planet. Planets of that mass regime can be terrestrial, ocean, or Neptune-like planets.”

NBC News notes that Gliese 163c orbits its parent star in just 26 days, while the second planet, Gliese 163b, takes just nine days to go around the red dwarf, which is considerably dimmer than our sun.
Gliese 163c ranks fifth on the list of alien worlds that are good candidates to host life, according to the The Planetary Habitability Laboratory (PHL) at the University of Puerto Rico at Arecibo, which keeps the log. PHL’s Abel Mendez adds that, “We are finding more potentially habitable planets now than before.”
out of the six planets currently on PHL’s list, four have been found in the last year, including Kepler-22b, Gliese 667Cc, HD 85512b, and the latest Gliese 163c. Mendez added that:

“Most of these are relatively close, so we can expect to find better and closer ones as our technological sensitivity to Earth-size planets improves.”

In order to rank their possible habitable planets, Mendez and his colleagues at PHL compare the possibles with Earth, ranking them on similar mass, diameters, and temperatures when compared to Earth. Temperatures are tough to estimate, however, because it is influenced by atmospheric characteristics, which scientists do not know much about using the equipment of today.
Bonfils and his team continue to use HARPS to find more planets that may sustain life, hoping that they can find one they can study today, instead of waiting for technology to catch up. Bonfils stated that, “Although it is nice to build the sample of possibly habitable planets that will be observed with the next generation of telescopes, it would be even better if we could find a planet one could characterize with today’s observatories.”