An Overview of Isotopic Anomalies in Extraterrestrial Materials and Their Nucleosynthetic Heritage

摘要

Isotopic anomalies are expected in primitive meteorites since astronomical observation and astrophysical modeling of stars predict a great variety of stellar processes. Protostellar clouds should partially preserve the memory of this diversity in solid grains. Since 1970, high precision-mass spectrometry and high resolution ion probes have led to the discovery of numerous isotopic anomalies, which were rapidly associated with nucleosynthetic processes. A general rule is that small isotopic effects (parts in 10~3-10~4) are observed in centimeter size samples, whereas order of magnitude variations are observed at the micron scale in circumstellargrains.