## Appendix: the angular momentum conservation model of wind accretion for barium stars: equationsFor the binary system, the two components (an intrinsic AGB star with mass , the present white dwarf, and a main sequence star with mass , the present barium star) rotating around the mass core C, so the total angular momentum is conservative in the mass core reference frame. If the two components exchange material through wind accretion, the angular momentum conservation of total system is showed by: where For the binary system, according to Huang (1956), the changes of
orbital elements, the orbital semi-major axis where According to the angular momentum conservation model, the term can be obtained from the following equation: thus then, we can obtain Thus The term is: Combining Eqs. (9), (10), (15) and (16), we can obtain the
changes of orbital semi-major axis © European Southern Observatory (ESO) 2000 Online publication: December 11, 2000 |