Subscribe free to our newsletters via your
. 24/7 Space News .

A Hot Potential Habitable Exoplanet around Gliese 163
by Staff Writers
Arecibo PR (SPX) Sep 05, 2012

Orbits and estimated relative sizes of the two innermost planets, b and c, around Gliese 163. An additional third unconfirmed planet, d, has an orbit outside the scale of the figure (not shown). Gliese 163c orbits within the inner regions of the habitable zone (green shade) making it hotter but still potentially habitable depending on its composition and atmospheric structure. CREDIT: PHL UPR Arecibo. For a larger version of this image please go here.

A new superterran exoplanet (aka Super-Earth) was found in the stellar habitable zone of the red dwarf star Gliese 163 by the European HARPS team. The planet, Gliese 163c, has a minimum mass of 6.9 Earth masses and takes nearly 26 days to orbit its star. Superterrans are those exoplanets between two and ten Earth masses, which are more likely composed of rock and water.

Gliese 163 is a nearby red dwarf star 50 light years away in the Dorado constellation. Another larger planet, Gliese 163b, was also found to orbit the star much closer with a nine days period. An additional third, but unconfirmed planet, might be orbiting the star much farther away.

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. In comparison, Venus receives 90% more light from the Sun than Earth.

We do not 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 60C. Most complex life on Earth (plants, animals, and even humans) are not able to survive at temperatures above 50C, however, plenty of extremophilic microbial life forms can thrive at those temperatures or higher.

The detection of potential habitable exoplanets is pacing up. There are now six including the debated Gliese 581g, most of them detected just in the last year. Four of these bodies, Gliese 581d, Gliese 667Cc, Gliese 581g, and now Gliese 163c are around red dwarf stars (M-star). HD 85512 is around a K-star (a middle star between the smaller red dwarfs and the Sun).

Only Kepler-22b is around a Sun-like star (G-star). All of these planets are bigger than Earth but still considered potentially habitable, at least to simple life forms. Scientists are trying to construct better ground and space observatories in the next decades to be able to detect smaller worlds, those more resembling Earth.

The Habitable Exoplanet Catalog of the Planetary Habitability Laboratory @ UPR Arecibo (, which was not involved in the discovery, now includes and ranks Gliese 163c as number five in its main list of best objects of interest for life.

The potential for habitable planets around red dwarf stars has been and issue of much debate. Tidal effects on the planets around these stars might cause extra surface heating or even tidal locking (always giving the same face to its parent star). 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. Our Solar System lacks an example of a superterran.

Its eight planets are either the smaller terrestrial kind, like Earth, or the larger gas giants, like Jupiter. Understanding superterrans around red dwarf stars, a non Sun-like star, just adds to the challenge of assessing their habitability.

The NASA 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 new exoplanets around Gliese 163 were discovered by the European HARPS team led by Xavier Bonfils from the UJF-Grenoble/CNRS-INSU, Institut de Plane 'tologie et d'Astrophysique of Grenoble, France. Other participating scientists are from France, Germany, Portugal, Switzerland, and Belgium.

Gliese 163c was announced by team member Thierry Forveille from the Observatoire de Grenoble during the International Astronomical Union session Formation, Detection, and Characterization of Extrasolar Habitable Planets from August 27th to 31st, 2012 in Beijing, China.

A paper was submitted to the scientific journal Astronomy and Astrophysics.


Related Links
Planetary Habitability Laboratory
HARPS Team Research Page
Habitable Exoplanet Catalog
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

NASA's Kepler Discovers Multiple Planets Orbiting a Pair of Stars
Washington DC (SPX) Sep 03, 2012
Coming less than a year after the announcement of the first circumbinary planet, Kepler-16b, NASA's Kepler mission has discovered multiple transiting planets orbiting two suns for the first time. This system, known as a circumbinary planetary system, is 4,900 light-years from Earth in the constellation Cygnus. This discovery proves that more than one planet can form and persist in the stre ... read more

NASA's GRAIL Moon Twins Begin Extended Mission Science

Flags at half mast across US for Armstrong funeral

Walls of Lunar Crater May Hold Patchy Ice, LRO Radar Finds

Russia's moonshot hope 'not a dream'

NASA's Mars rover parked to test robotic arm

Curiosity Has a Photo Day

Marks of Laser Exam on Martian Soil

Opportunity Drives And Images Rock Outcrop

Space-age food served up with seeds of success

Africa eyes joint space agency

Africa needs own space agency: Sudan's Bashir

Moles, crabs and Moon dust: DLR at the ILA Space Pavilion

Tiangong Orbit Change Signals Likely Date for Shenzhou 10

China Focus: Timeline for China's space research revealed

China eyes next lunar landing as US scales back

China unveils ambitious space projects

ISS crew complete space station repair

Crew Wraps Up Preparations for Wednesday's Spacewalk

Building MLM Under Way at Khrunichev

Astronauts Complete Second Expedition 32 Spacewalk

First-Stage Fuel Loaded; Launch Weather Forecast Improves

NASA launches mission to explore radiation belts

ISRO to score 100 with a cooperative mission Sep 9

NASA Administrator Announces New Commercial Crew And Cargo Milestones

Birth of a planet

A Hot Potential Habitable Exoplanet around Gliese 163

NASA's Kepler Discovers Multiple Planets Orbiting a Pair of Stars

How Old are the First Planets?

Amazon takes on iPad with new Kindle Fire tablet

US judge OKs partial settlement in e-book case

Empire-style computers? Frenchman takes PCs to lap of luxury

Google-Microsoft field smartphones to take on iPhone 5

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement