  A star that wanders too close to a massive black hole (BH) is shredded by the
BH's tidal gravity. Stellar gas falls back to the BH, releasing a flare of
energy. In anticipation of upcoming transient surveys, we predict the light
curves and spectra of tidal flares as a function of time, highlighting the
unique signatures of tidal flares in the optical and near-IR. Some of the gas
initially bound to the BH is likely blown away when the fallback rate is
super-Eddington at early times. This outflow produces an optical luminosity
comparable to that of a supernova; such events have durations of ~10 days and
may have been missed in supernova searches that exclude the nuclear regions of
galaxies. When the fallback rate subsides below Eddington, the gas accretes
onto the BH via a thin disk whose emission peaks in the UV to soft X-rays. Some
of this emission is reprocessed by the unbound stellar debris, producing a
spectrum of very broad emission lines (with no corresponding narrow forbidden
lines). These lines are strongest for BHs with MBH ~ 10^5 - 10^6 Msun and thus
optical surveys are particularly sensitive to the lowest mass BHs in galactic
nuclei. Calibrating our models to ROSAT and GALEX observations, we predict
detection rates for Pan-STARRS, PTF, and LSST and highlight observational
challenges in the optical. Pan-STARRS should detect at least several events per
year--many more if current theoretical models of super-Eddington outflows are
correct. These surveys will significantly improve our knowledge of stellar
dynamics in galactic nuclei, the physics of super-Eddington accretion, the
demography of intermediate mass BHs, and the role of tidal disruption in the
growth of massive BHs.
