Astrophysical Neutrino Telescopes

This review describes telescopes designed to study neutrinos from astrophysical sources. These sources include the Sun and Supernovae emitting neutrino energies up to tens of MeV, atmospheric neutrino sources caused by cosmic ray interactions and other sources generating neutrino energies ranging up to $1\times 10^{20}$ eV. Measurements with these telescopes also provide information on neutrino properties including clear evidence for neutrino flavor change. Telescopes in operation in the past and present are described, along with plans for future instruments to expand this rapidly growing field of particle astrophysics.