More Images of Neon Abundance in Nearby Stars
1
Chandra X-ray Spectrum of II Pegasi
Chandra was used to measure the neon abundance in 21 Sun-like stars within a distance of 400 light years. The spectrum of one of these objects, II Pegasi, is shown above. The relative amount of neon in these stars was, on average, almost three
times more neon than is measured for the Sun, just the amount needed to
bring the solar oscillation observations and the theoretical model into
agreement. II Pegasi was observed by Chandra on October 17, 1999 for 12 hours.
(Credit: NASA/CXC/J.Drake & P.Testa)
2
Illustration of Convection in Sun-like Star
Neon, along with atoms of carbon, nitrogen and oxygen, plays an
important role in regulating the rate at which energy flows from nuclear
reactions in the Sun's core to its surface. The character of the energy
flow changes dramatically about 125,000 miles from the surface on the
Sun, where the stately diffusion of heat suddenly converts to a
convective motion much like the unstable air in a thunderstorm.
(Illustration: NASA/CXC/M.Weiss)
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