Hello All!   
      
   Fried Planets        
      
   Oct. 25, 2012:   An international team of astronomers has caught a star in the   
   act of devouring one of its planets. BD+48 740, a red giant they observed   
   using the 9.2-meter Hobby-Eberly Telescope at the McDonald Observatory in   
   Texas, appears to have the fumes of a scorched planet in its atmosphere.  This   
   is consistent with a rocky world, recently destroyed.   
      
   Could the same thing happen to Earth?    
      
   Yes indeed, says Alex Wolszczan, a member of the research team from Penn State   
   University: "A similar fate may await the inner planets in our solar system   
   when the sun becomes a red giant some five billion years from now."    
      
   http://www.youtube.com/watch?v=21RkSui1cG8   
      
   A new ScienceCast video looks into the case of the planet-devouring red giant   
   BD+48 740. Play it! Researchers who specialize in stellar evolution have long   
   known that the inner planets are in danger.  The trouble starts in the distant   
   future when the sun's core runs out of hydrogen fuel for nuclear fusion. To   
   keep the fires burning, the sun will begin to fuse hydrogen outside the core,   
   in a layer closer to the stellar surface. This will turn the sun into a red   
   giant, at least 200 times wider than it is today. Mercury, Venus, Earth and   
   possibly even Mars could be engulfed.    
      
   The fate of Earth is not a certainty, however. Some researchers believe that   
   Earth's orbit might spiral outward, keeping the planet at a safe distance from   
   the approaching inferno.  This could happen if solar winds carry away a   
   significant fraction of the sun's mass in the years leading up to the red   
   giant phase.   
      
   On the other hand, the sun might expand so quickly that our planet has no   
   chance to escape.  Earth would get caught in the sun's rapidly advancing   
   atmosphere and spiral inward to oblivion.   
      
   Observations of red giant BD+48 740 lend credence to the second possibility.    
      
   http://inspirehep.net/record/1119043/plots   
      
   A spectroscopic analysis of light from BD+48 740 reveals lithium fumes in the   
   star's atmosphere. [more] "Our detailed spectroscopic analysis of BD+48 740   
   reveals that the red giant contains an abnormally high amount of lithium,"   
   says Monika Adamow who led the study at the Nicolaus Copernicus University in   
   Torun, Poland.    
      
   Because lithium is easily destroyed in stars, finding lots of it in an old red   
   giant is unexpected.  The most likely source is a planet. Wolszczan explains:   
   "It is probable that the lithium production in BD+48 740 was triggered by a   
   mass the size of a planet that spiraled into the star and heated up while the   
   star was digesting it."    
      
   The team found another piece of evidence, too. BD+48 740 has a gas giant   
   planet 1.6 times bigger than Jupiter which has not yet been devoured.  The big   
   planet has a highly elliptical orbit. In fact, it is the most elliptical orbit   
   ever found for a planet around an older star. Its orbit, which almost surely   
   started out circular, was probably altered by some catastrophic event--like   
   its star having an inner planet for lunch.   
      
   One day, he says, our own solar system may end up the same way.  In five   
   billion years, the fried planet could be Earth.   
      
   The original research of Adamov et al may be found in their article "BD+48 740   
   - Li overabundant giant star with a planet. A case of recent engulfment?"    
      
      
   Author: Dr. Tony Phillips| Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
      
      
   Regards,   
      
   Roger    
   --- timEd/386 1.10.y2k+   
    * Origin: NCS BBS - Houma, LoUiSiAna - (1:3828/7)