Binary population synthesis(BPS),an approach to evolving millions of stars(including binaries) simultaneously,plays a crucial role in our understanding of stellar physics,the structure and evolution of galaxies,and co...Binary population synthesis(BPS),an approach to evolving millions of stars(including binaries) simultaneously,plays a crucial role in our understanding of stellar physics,the structure and evolution of galaxies,and cosmology.We proposed and developed a BPS approach,and used it to investigate the formation of many peculiar stars such as hot subdwarf stars,progenitors of type la supernovae,barium stars, CH stars,planetary nebulae,double white dwarfs,blue stragglers,contact binaries,etc.We also established an evolution population synthesis(EPS) model,the Yunnan Model,which takes into account binary interactions for the first time.We applied our model for the origin of hot subdwarf stars in the study of elliptical galaxies and explained their far-UV radiation.展开更多
To understand the formation mechanism of blue stragglers in open clusters, we conducted a photometric analysis for a blue straggler eclipsing binary in the old open cluster NGC 2141. By using the least square fitting ...To understand the formation mechanism of blue stragglers in open clusters, we conducted a photometric analysis for a blue straggler eclipsing binary in the old open cluster NGC 2141. By using the least square fitting of times of minima, we derived the ephemeris and redetermined the orbital period of this system to be 0.6227 d. We have also done a photometric analysis for light curve with the Wilson-Devinney Code （2003）. The photometric solutions reveal a semi-detached binary with the second- ary component filling its Roche lobe. The photometric mass ratio MJMI （secondary/primary） was determined to be 0.190_＋0.002 and the ratio of V-band luminosity L2/LI（V） is about 0.033_＋0.001, which indicates the secondary component is overluminous. Thus, this blue straggler likely results from a substantial mass exchange between these two components.展开更多
文摘Binary population synthesis(BPS),an approach to evolving millions of stars(including binaries) simultaneously,plays a crucial role in our understanding of stellar physics,the structure and evolution of galaxies,and cosmology.We proposed and developed a BPS approach,and used it to investigate the formation of many peculiar stars such as hot subdwarf stars,progenitors of type la supernovae,barium stars, CH stars,planetary nebulae,double white dwarfs,blue stragglers,contact binaries,etc.We also established an evolution population synthesis(EPS) model,the Yunnan Model,which takes into account binary interactions for the first time.We applied our model for the origin of hot subdwarf stars in the study of elliptical galaxies and explained their far-UV radiation.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11033008 and 11103072)the Chinese Academy of Sciences (Grant No. KJCX2-YW-T24)the National Basic Research Program of China (Grant No. 2009CB824800)
文摘To understand the formation mechanism of blue stragglers in open clusters, we conducted a photometric analysis for a blue straggler eclipsing binary in the old open cluster NGC 2141. By using the least square fitting of times of minima, we derived the ephemeris and redetermined the orbital period of this system to be 0.6227 d. We have also done a photometric analysis for light curve with the Wilson-Devinney Code （2003）. The photometric solutions reveal a semi-detached binary with the second- ary component filling its Roche lobe. The photometric mass ratio MJMI （secondary/primary） was determined to be 0.190_＋0.002 and the ratio of V-band luminosity L2/LI（V） is about 0.033_＋0.001, which indicates the secondary component is overluminous. Thus, this blue straggler likely results from a substantial mass exchange between these two components.
