Type IIn supernovae ( SNe IIn ) dominate the brightest supernova events in observed FUV flux ( \sim 1200 - 2000 Å ) .
We show that multi-band , multi-epoch optical surveys complete to m _ { r } = 27 can detect the FUV emission of \sim 25 z > 2 SNe IIn deg ^ { -2 } yr ^ { -1 } rest-frame ( \sim 10 SNe IIn deg ^ { -2 } yr ^ { -1 } observed-frame ) to 4 \sigma using a technique monitoring color-selected galaxies .
Moreover , the strength and evolution of the bright emission lines observed in low-redshift SNe IIn imply that the Ly \alpha emission features in \sim 70 % of z > 2 SNe IIn are above 8m-class telescope spectroscopic thresholds for \sim 2 yr rest-frame .
As a result , existing facilities have the capability to both photometrically detect and spectroscopically confirm z > 2 SNe IIn and pave the way for efficient searches by future 8m-class survey and 30m-class telescopes .
The method presented here uses the sensitivities and wide-field capabilities of current optical instruments and exploits ( 1 ) the efficiency of z > 2 galaxy color-selection techniques , ( 2 ) the intrinsic brightness distribution ( \langle M _ { B } \rangle = -19.0 \pm 0.9 ) and blue profile of SNe IIn continua , ( 3 ) the presence of extremely bright , long-lived emission features , and ( 4 ) the potential to detect blueshifted SNe Ly- \alpha emission shortward of host galaxy Ly- \alpha features .