Stellar burning lifetimes

Guided by early compilations of the cosmic abundances as reflected in solar system material (e.g., Suess and Urey, 1956), Burbidge cr a/. (1957) and Cameron (1957) identified the nuclear processes by which element formation occurs in stellar and supernova environments (i) hydrogen burning, which powers stars for —90% of their lifetimes (ii) helium burning, which is responsible for the production of and the two most abundant elements heavier than helium (iii) the a-process, which we now understand as a combination of... 

Stellar evolution and nucleosynthesis- Nuclear burnings take place in the stellar interiors during the star lifetime and produce new chemical elements, in particular metals. 

Supernovae. All stars above an original mass of more than 8 solar masses are expected to explode at the end of their lifetime after they have exhausted nuclear burning the observable effect of such an explosion is called a supernova. When they explode, they emit about 3 x 10 ° ergs in neutrinos and also about 10 erg in visible energy, such as in shock waves in ordinary matter, the former stellar... 

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