Supernovae and their Cosmological Implications

                     Alex Filippenko
           University of California at Berkeley


   Supernovae are extremely luminous, can be individually calibrated,
are reasonably well understood, and should be fairly insensitive to
evolutionary effects. They therefore have enormous potential for the
determination of fundamental cosmological quantities such as the
Hubble parameter, the mass density of the Universe, and the
cosmological constant. They can also be used to show that large
redshifts are consistent with the expansion of space, rather than with
some competing hypotheses such as "tired light."  As with any
cosmological yardstick, however, great care is required to obtain
accurate results. In this talk I will review the use of supernovae
as cosmological probes, highlighting the main conclusions achieved 
thus far and providing a preview of coming attractions.