近20年中在银河系及河外星系中同位素丰度比12C/13C的毫米波及
光学观测取得了一些结果，同位素丰度比12C/13C在研究恒星演化及其
核过程方面具有重要的
意义。银河系中的12C/13C随银心距DGC呈梯度分布，附近河外星系中明显较高的
12C/13C表明银河系中心处于一个较为宁静的物理相，恒星中不同的12C/13C值则反
映了各自不同的演化阶段。进一步高精度、大样本的观测将有助于人们更加细
致地了解恒星演化及其核过程。
On Relations of 12C/13C Isotope Ratio and Stellar Evolution and Nucleosynthesis
Mao Ruiqing Zeng Qin
Purple Mountain Observatory,The Chinese Academy of Sciences, Nanjing 210008)
(Joint Radio Astronomy Laboratory, The Chinese Academy of Sciences, Nanjing 210008)
Abstract
A brief review is given for 12C/13C isotope ratio in the Galaxy and
extragalaxy based on the mm-wave and optical observational results, and the relations of 12C/13C isotope ratio and stellar evolution and
nucleosynthesis are also introduced. There is a gradient in the 12C/13C ratio
with DGC in the Galaxy. From the comparison of Galactic and extragalactic
12C/13C ratio it is indicated that the nuclear region of the Galaxy has been
quiescent for a long time. The difference of the 12C/13C ratio in stars is a
reflection of their different evolution phase. More accurate observations are needed for us to study the stellar evolution and its nuclear process in more detail.
Key words isotope ratio---stellar evolution---nucleosynthesis