Structure and evolution of the tidally heated hot-Jupiter KELT-9b

The hot Jupiter KELT-9b is observed to have a strong intrinsic heat flux T_int ~ 2400 +/- 800 K. However, requesting a bulk metallicity  Z<20% requires significantly lower T_int. To resolve this discrepancy, we suggest (obliquity) tidal heating in a shell and a static k2 < 0.1.