We report the discovery of five very cool white dwarfs in the Sloan Digital Sky Survey ( SDSS ) .
Four are ultracool , exhibiting strong collision induced absorption ( CIA ) from molecular hydrogen and are similar in color to the three previously known coolest white dwarfs , SDSS J1337+00 , LHS 3250 and LHS 1402 .
The fifth , an ultracool white dwarf candidate , shows milder CIA flux suppression and has a color and spectral shape similar to WD 0346+246 .
All five new white dwarfs are faint ( g > 18.9 ) and have significant proper motions .
One of the new ultracool white dwarfs , SDSS J0947 , appears to be in a binary system with a slightly warmer ( T _ { eff } \sim 5000 K ) white dwarf companion .