Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

Stardust: From Planetary Nebulae to the Solar System

Sun Kwok
Institute of Astronomy and Astrophysics, Academia Sinica

Friday, January 14, 2005
11:30 AM @ Stirling A

Abstract:

Recent observations by the Infrared Space Observatory (ISO) have found evidence of rapid synthesis of complex organic molecules in the late stages of stellar evolution. The chemical synthesis begins with the formation of acetylene, the first building block of benzene, in carbon stars. In a following proto-planetary nebulae stage, emission features corresponding to stretching and bending modes of aliphatic compounds are detected. When these objects evolve to become planetary nebulae, aromatic C-H and C-C stretching and bending modes become strong. These results show that complex carbonaceous compounds can be produced in a circumstellar environment over a period of only a few thousand years.

Isotopic analysis of meteorites and interplanetary dust collected in the upper atmospheres have revealed the presence of pre-solar grains similar to those formed in evolved stars. This provides a direct link between star dust and the solar system and raises the possibility that the early solar system was chemically enriched by stellar ejecta.

All are welcome! Refreshments will be available after the talk. Dr. Kwok will be giving a public lecture in the evening for the Royal Astronomical Society of Canada, details to follow.