Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars

  title={Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars},
  author={Timothy R. Bedding and Beno{\^i}t Mosser and Daniel Huber and Josefina Montalb{\'a}n and Paul G. Beck and J{\o}rgen Christensen-Dalsgaard and Yvonne P. Elsworth and Rafael A. Garc{\'i}a and Andrea Miglio and Dennis Stello and Timothy R. White and Joris De Ridder and Saskia Hekker and Conny Aerts and Caroline Barban and K'evin Belkacem and A.-M. Broomhall and Timothy M. Brown and Derek L. Buzasi and Fabien Carrier and William J. Chaplin and Maria Pia di Mauro and M-A. Dupret and S{\o}ren Frandsen and Ronald L. Gilliland and Marie Jo Goupil and Jon M. Jenkins and Thomas Kallinger and Steven D. Kawaler and Hans Kjeldsen and Savita Mathur and Arlette Noels and V{\'i}ctor Silva Aguirre and Paolo Ventura},
Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include uncertainties in the amount of mass lost at the surface before helium ignition and the amount of internal mixing from rotation and other processes. Progress is hampered by our inability to distinguish between red… 
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