  We analytically investigate the spin-1 quasinormal mode frequencies of
Schwarzschild black hole space-time. We formally determine these frequencies to
arbitrary order as an expansion for large imaginary part (i.e., large-n, where
n is the overtone number). As an example of the practicality of this formal
procedure, we explicitly calculate the asymptotic behaviour of the frequencies
up to order $n^{-5/2}$.
