  We present photometric typing analyses of three young supernovae observed
with the Robotic 60-inch Telescope at Palomar Observatory (P60). This
represents the first time that such photo-typing has been attempted, in a blind
fashion, on newly-discovered supernovae. For one of the target supernovae,
SN2004cs, our photometry provided the first constraint on the SN type, which we
predicted would be type Ia. To the contrary, however, our subsequent Keck
spectroscopy shows it to be an unusual type II supernova. For each of the other
two supernovae, SN2004dh (type II) and SN2004dk (type Ib), our photo-typing
results are consistent with the known type of the event as determined from
ground-based spectroscopy; however, the colors of SN2004dk are also consistent
with a type Ic or type II classification. We discuss our approach to the
challenges of photo-typing - contamination by host galaxy light and the unknown
photometric quality of the data - in the case where it is desirable to complete
the analysis with just one night of observations. The growing interest in the
properties and behavior of very young supernovae, and the increased discovery
rate for such events, mean that prompt photo-typing analyses can provide useful
input to observational campaigns. Our results demonstrate the value and
feasibility of such a project for P60, at the same time illustrating its chief
inherent shortcoming: an inability to identify new and unusual events as such
without later spectroscopic observations.
