  Let $K$ be a number field and, for an integral ideal $\mathfrak{q}$ of $K$,
let $\chi$ be a character of the narrow ray class group modulo $\mathfrak{q}$.
We establish various new and improved explicit results, with effective
dependence on $K$, $\mathfrak{q}$ and $\chi$, regarding the zeros of the Hecke
L-function $L(s,\chi)$, such as zero-free regions, Deuring-Heilbronn
phenomenon, and zero density estimates.
