CHED 1625 |
| When stars die, most of their mass, including newly synthesized elements, reintegrates into the interstellar medium. Dwarf stars like the sun evolve into red giant stars, which shed their atmospheres and become enshrouded by cool circumstellar shells. There formation of molecular gases and condensation of refractory solids, such as corundum, spinel, graphite, and SiC, takes place. Stars initially larger than 10 solar masses end their lives in supernova explosions, and their ejecta also turn dusty during cooling. Astronomical observation can probe the gas and dust chemistry in these environments. However, genuine stardust from giant stars and supernovae was discovered in meteorites about 20 years ago. Since then laboratory astronomy of this dust provided many details about stellar element and isotope production, and about gas and dust formation conditions in giant stars and supernovae. |
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Chemical Evolution, Chemical Change Across Space and Time
1:30 PM-4:45 PM, Tuesday, March 27, 2007 McCormick Place North -- Room N227A, Level 2, Oral
Division of Chemical Education |