Thursday, May 24, 2012

Kepler Sees a Possibly-Evaporating Exoplanet


The above image is an artist's concept of the comet-like tail that may be trailing from a super Mercury-size planet candidate as it transits its parent star, KIC 12557548. Image Credit: NASA/JPL-Caltech

What a switch! Astronomers have seen comets disintegrate as they circle too closely around our star. But now, using NASA's Kepler mission, astronomers may have detected evidence of an exoplanet candidate 1,500 light-years away from Earth, disintegrating under the searing heat of its own star.

This super Mercury-size planet appears to be trailing debris similar to a comet. But if this is correct, the planet won't last for long. Scientists calculate that, at the current rate of evaporation, the dusty world could be completely vaporized within 200 million years.

Launched March 2009, the Kepler observatory mission detects planets and planet candidates by measuring dips in the brightness of more than 150,000 stars to search for planets crossing in front of — transiting — their stars. The current commotion started when astronomers identified an unusual light pattern emanating from a star named KIC 12557548, one of those in Kepler's field-of-view.

Orbiting a star smaller and cooler than our sun, the planet candidate completes its orbit in less than 16 hours — making it one of the shortest orbits ever detected. At an orbital distance of only twice the diameter of its star, the surface temperature of the planet is estimated to be a smoldering 3,300 degrees Fahrenheit (1,816 degrees Celsius).

Scientists think that the star-facing side of the potentially rocky inferno is an ocean of seething magma. The surface melts and evaporates at such high temperatures that the energy from the resulting wind is great enough to allow dust and gas to escape into space. This dusty effluence trails behind the body as it disintegrates around the star.

Additional follow-up observations are needed to confirm the candidate as a planet. More details on the finding can be found in a Massachusetts Institute of Technology news release at: web.mit.edu/newsoffice/2012/dusty-exoplanet-0517.html .

A technical paper is published in The Astrophysical Journal and is available for download at: arxiv.org/abs/1201.2662 .

And now, the mission particulars...

NASA's Ames Research Center in Moffett Field, California, manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory, Pasadena, California, managed the Kepler mission's development. Ball Aerospace and Technologies Corp. in Boulder, Colorado, developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

For more information about the Kepler mission, visit: www.nasa.gov/kepler .

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