Gravitational darkening coefficients of the stars in the semidetached binary V Puppis

We have analyzed high-precision vby light curvesfor the semi-detached binary V Pup in a Roche model. They are consistent with the standard gravitational darkening coefficient for hot stars, β = 0.25, rather than the value β = 1.36 ± 0.04 derived by Kitamura and Nakamura 1] using a simpler model. We rigorously estimate the confidence intervals for the allowed gravitational darkening coefficients for a star filling its Roche lobe to be β = (?0.24, +1.29) for the 99% confidence level and β = (?0.21, +1.26) for the 67% confidence level.