  Helioseismological sound-speed profiles severely constrain possible
deviations from standard solar models, allowing us to derive new limits on
anomalous solar energy losses by the Primakoff emission of axions. For an
axion-photon coupling $g_{a\gamma} < 5 x 10^(-10) GeV^(-1)$ the solar model is
almost indistinguishable from the standard case, while $g_{a\gamma} > 10 x
10^(-10) GeV^(-1)$ is probably excluded, corresponding to an axion luminosity
of about $0.20 L_(sun)$. This constraint on $g_{a\gamma}$ is much weaker than
the well-known globular-cluster limit, but about a factor of 3 more restrictive
than previous solar limits. Our result is primarily of interest to the large
number of current or proposed search experiments for solar axions because our
limit defines the maximum g_{a\gamma}$ for which it is self-consistent to use a
standard solar model to calculate the axion luminosity.
