Astrophysical S-factors from asymptotic normalization coefficients

S-factors for direct capture reactions can be found at astrophysical energi es from asymptotic normalization coefficients which provide the normalizati on of the tail of the overlap function. For example the overlap for B-8 --> Be-7 + p defines the S-factor for Be-7 (p, gamma)B-8. Peripheral transfer reactions offer a technique to determine these asymptotic normalization coe fficients. As a test of the technique, the O-16(He-3, d)F-17 reaction has b een used to determine asymptotic normalization coefficients for transitions to the ground and first excited states of F-17. The S-factors for O-16(p, gamma)F-17 calculated from these F-17 --> O-16 + p asymptotic normalization coefficients are found to be in very good agreement with recent measuremen ts. Following the same technique, the B-10(Be-7, B-8)Be-9 and N-14(Be-7, B- 8)C-13 reactions have been used to measure the asymptotic normalization coe fficient for Be-7(p, gamma)B-8. This result provides an indirect determinat ion of S-17(0).