Nearby Mars-Sized Exo-Planet Discovered Orbiting a Red DwarfThe Daily Galaxy --Great Discoveries Channel: Sci, Space, TechFollow the Daily Galaxy
« "The Electric Universe" --A New NASA Mission |Main| World's 1st Free Course on "Astrobiology and the Search for Extraterrestrial Life" »July 18, 2012 Nearby Mars-Sized Exo-Planet Discovered Orbiting a Red Dwarf
The University of Central Florida has detected what could be its first planet, only two-thirds the size of Earth and located right around the corner, cosmically speaking, at a mere 33 light- years away. The exoplanet candidate called UCF 1.01, is close to its star, orbiting the star in 1.4 days. The planet's surface likely reaches temperatures of more than 1,000 degrees Fahrenheit. The discoverers believe that it has no atmosphere, is only two-thirds the gravity of Earth and that its surface may be volcanic or molten.
"We have found strong evidence for a very small, very hot and very close-by planet with the help of the Spitzer Space Telescope," said Kevin Stevenson, a recent Ph.D graduate from the UCF and lead author of the paper, which appears online tomorrow in The Astrophysical Journal. "This discovery is a significant accomplishment for UCF."Stevenson and his colleagues were studying a hot-Neptune exoplanet, designated GJ 436b, already known to exist around the red-dwarf star GJ 436, when data revealed clues that led them to suspect there could be at least one new planet in that system, perhaps two.
The team noticed slight dips in the amount of infrared light streaming from the star. A review of Spitzer archival data showed that the dips were periodic, suggesting that a planet might be blocking out a small fraction of light as it passed in front of GJ 436, as seen from Earth. * "I could see these faint dips in the starlight and I wanted to determine their source. I knew that if these signals were periodic, they could be from an unknown planet," said Stevenson, who is now a postdoctoral scholar at the University of Chicago.
So he, UCF planetary sciences professor Joseph Harrington and UCF graduate student Nate Lust began looking at the data. They sifted through hundreds of hours of observations collected from Spitzer, the Deep Impact spacecraft, the ground-based Very Large Telescope in Chile and the Canada-France-Hawaii Telescope near the summit of Mauna Kea in Hawaii.
This transit technique, used by a number of telescopes, including NASA's Kepler space telescope, relies on these tiny, partial eclipses to find exoplanet candidates. Spitzer has performed science work on known exoplanets before, but UCF-1.01 represents the first time Spitzer has made a transit discovery. With the finding of UCF-1.01, GJ 436 is likely now home to the first multi-transiting-planet system described by a mission other than Kepler.
Of the 1,800 stars identified by Kepler as candidates for having planetary systems, only three are verified to contain sub-Earth size exoplanets. The depth and duration of a transit reveals basic properties of an exoplanet, such as its size and distance from a host star.
In UCF-1.01's case, its diameter is estimated at 5,200 miles, or two-thirds that of Earth, placing the world among the smallest on record. The team also noticed hints of yet another potential planet dubbed UCF-1.02, but its period was impossible to estimate.
So why aren't scientists calling UCF-1.01 a planet? A measured mass is needed to verify that these objects are planets, but even the most sensitive instruments currently available are unable to measure exoplanet masses this small. "Despite the lack of a confirmed mass, the team is confident future observations will verify our findings," Harrington said.
"I hope future observations will confirm these exciting results, which show Spitzer may be able to discover exoplanets as small as Mars," said Michael Werner, Spitzer Project Scientist at JPL. "Even after almost nine years in space, Spitzer's observations continue to take us in new and important scientific directions."
Journal reference: Astrophysical Journal
The Daily Galaxy via University of Central Florida
Posted at 11:30 AM | PermalinkComments
Two quick things! FIRST: This is NOT the only OTHER multiolanet trasiting system other than those discivered by the Kepler spacecraft! CoRoT found two neptune sized planets transiting the same star about a year ago! SECOND: IF you use the Kepler teams' paradigm that ALL multitransiting systems are almost certainly real planets, then you may not need UCF1.01's mass to confirm it as a planet! ALSO: Continued observations by Spitzer should show considerable transit timing variations (TTV'S) of UCF1.01 due to its nearness at conjonction (about the same as in the KEPLER 36 system) to the much more massive Gliese 436b AND, the APPARENT 2 to 1 mean motion resinance between the two.
Posted by:Harry R Ray |July 19, 2012 at 07:30 AMPost a comment
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