Spindown of neutron stars in close binary systems

Consideration is given to the way the rotation period of a magnetic neutron star, initially spinning rapidly, evolves when the neutron star is a member of a close binary system in which the companion is a massive main-sequence star losing mass by a stellar wind. A new model is developed for the spindown process that describes how the interactions at the boundary of the magnetosphere affect the surrounding material (which originates from the stellar wind). Spindown time-scales are calculated and hence constraints on the parameters of the system are obtained which determine in what circumstances spindown to long periods is possible. (author)