EFFECT OF GAS-PRESSURE IN THEORY OF LINE ACCRETION .1.

The Bondi-Hoyle equation of line accretion is modified by taking into account a pressure term and is supplemented by Bernoulli's equation which expresses the conservation of energy. It is shown that for physically interesting values of 7 (specific heats ratio) there exists a unique solution such that the gas velocity is subsonic near the stagnation point but supersonic beyond the sonic transition and asymptotically approaches Kx>, the unperturbed relative velocity. In addition, there exists an infinity of solutions such that the velocity is thoroughly subsonic and approaches the value (7 - 1) Vooliy + 1) at great distance from the star. This situation is analogous to the spherically symmetric accretion discussed by Bondi. The retarding force due to the intermediate solution [(7 - 1) K»/(7 + 1)] is thus greater than the Bondi-Hoyle case by a factor of (7 + l)/(7 - 1). The Lyttleton slow solution is formally obtained by letting 7 -> 1. © Royal Astronomical Society.