  We discuss in detail the information on large extra dimensions which can be
derived in the framework of stellar evolution theory and observation. The main
effect of large extra dimensions arises from the production of the Kaluza-Klein
(KK) excitations of the graviton. The KK-graviton and matter interactions are
of gravitational strength, so the KK states never become thermalized and always
freely escape. In this paper we first pay attention to the sun. Production of
KK gravitons is incompatible with helioseismic constraints unless the 4+n
dimensional Planck mass M_s exceeds 300 Gev/c^2. Next we show that stellar
structures in their advanced phase of H burning evolution put much more severe
constraints, M_s > 3-4 TeV/c^2, improving on current laboratory lower limits.
