  Supernovae (SNe), kilonovae (KNe), tidal disruption events (TDEs), optical
afterglows of gamma ray bursts (GRBs), and many other optical transients are
important phenomena in time-domain astronomy. Fitting the multi-band light
curves (LCs) or the synthesized (pseudo-)bolometric LCs can be used to
constrain the physical properties of optical transients. The (UV absorbed)
blackbody module is one of the most important modules used to fit the
multi-band LCs of optical transients having (UV absorbed) blackbody spectral
energy distributions (SEDs). We find, however, that the SEDs of some SNe show
UV excesses, which cannot be fitted by the model including a (UV absorbed)
blackbody module. We construct the bolometric LCs and employ the (cooling plus)
\Ni model to fit the constructed bolometric LCs, obtaining decent fits. Our
results demonstrate that the optical transients showing UV excesses cannot be
fitted by the multi-band models that include (UV-absorbed) blackbody module,
but can be well modeled by constructing and fitting their bolometric LCs.
