  We propose that the unstable 3.9days photometric periodicity of the hot
subdwarf (sdO) KIC10449976 results from a tidally locked planet that is heated
to 5000K by the UV radiation from the hot sdO star. Although the bolometric
radiation from the planet is very small relative to that of the star, in the
visible band the planet contributes 0.07% of the light, sufficient to explain
the observed periodic behavior. In our proposed scenario the stochastic
variations in period and light amplitude are attributed to weather on the
planet. Namely, streams on the surface and thermal variations in the planet's
atmosphere that are driven by the heating and by the planet rotation lead to
stochastic changes in the amount of radiation emitted by the planets. We
predict that a careful monitoring will reveal a gas giant planet at an orbital
separation of 8.3Rsun from KIC10449976.
