A specific form of this process that occurs for about a day maintains a state of quasi-equilibrium but not true statistical equilibrium. This process defines a stellar timescale whose numerator has a 0.007 coefficient, and is around 10-to-the-4th that of the Kelvin–Helmholtz timescale. Different mechanisms for this physical process have temperature dependencies of T-to-the-17 and T-to-the-41. In the Gamow window, this process is enhanced by quantum tunneling through the Coulomb barrier. (10[2])This process progressively begins in increasingly outward shells, forming (10[1])an onion-like structure, during evolution (10[1])of massive stars. (-5[1])This process occurs to hydrogen through the CNO cycle (10[1])and the proton–proton (10[1])chain. (10[1])For 10 points, name this process that powers stars, in which two nuclei combine to form a larger nucleus. (10[1])■END■