  We present ultravioliet (UV) observations of supernovae (SNe) obtained with
the UltraViolet/Optical Telescope (UVOT) on board the Swift spacecraft. This is
the largest sample of UV light curves from any single instrument and covers all
major SN types and most subtypes. The UV light curves of SNe Ia are fairly
homogenous while SNe Ib/c and IIP show more variety in their light curve
shapes. The UV-optical colors clearly differentiate SNe Ia and IIP,
particularly at early times. The color evolution of SNe IIP, however, makes
their colors similar to SNe Ia at about 20 days after explosion. SNe Ib/c are
shown to have varied UV-optical colors. The use of UV colors to help type SNe
will be important for high redshift SNe discovered in optical observations.
These data can be added to ground based optical and near infrared data to
create bolometric light curves of individual objects and as checks on generic
bolometric corrections used in the absence of UV data. This sample can also be
compared with rest-frame UV observations of high redshift SNe observed at
optical wavelengths.
