  Measuring the obliquity distribution of stars hosting warm Jupiters may help
us to understand the formation of close-orbiting gas giants. Few such
measurements have been performed due to practical difficulties in scheduling
observations of the relatively infrequent and long-duration transits of warm
Jupiters. Here, we report a measurement of the Rossiter-McLaughlin effect for
K2-232b, a warm Jupiter (M_P=0.39 M_Jup) on an 11.17-day orbit with an
eccentricity of 0.26. The data were obtained with the Automated Planet Finder
during two separate transits. The planet's orbit appears to be well-aligned
with the spin axis of the host star, with a projected spin-orbit angle of
lambda = -11.1+/-6.6 deg. Combined with the other available data, we find that
high obliquities are almost exclusively associated with planets that either
have an orbital separation greater than 10 stellar radii or orbit stars with
effective temperatures hotter than 6,000K. This pattern suggests that the
obliquities of the closest-orbiting giant planets around cooler stars have been
damped by tidal effects.
