We report the detection of a large amplitude MIR outburst in the white dwarf ( WD ) 0145+234 in the NEOWISE Survey data .
The source had a stable MIR flux before 2018 , and was brightened by about 1.0 magnitude in the W1 and W2 bands within half a year and has been continuously brightening since then .
No significant variations are found in the optical photometry data during the same period .
This suggests that this MIR outburst is caused by recent replenishing or redistribution of dust , rather than intrinsic variations of the WD .
SED modeling of 0145+234 suggests that there was already a dust disk around the WD in the quiescent state , and both of the temperature and surface area of the disk evolved rapidly since the outburst .
The dust temperature was \simeq 1770K in the initial rising phase , close to the sublimation temperature of silicate grains , and gradually cooled down to around 1150K , while the surface area increased by a factor of about 6 during the same period .
The inferred closest distance of dust to the WD is within the tidal disruption radius of a gravitationally bounded asteroid .
We estimated the dust mass to be between 3 \times 10 ^ { 15 } to 3 \times 10 ^ { 17 } \rho / ( 1 \mathrm { g } ~ { } cm ^ { -3 } ) kg for silicate grains of a power-law size distribution with a high cutoff size from 0.1 to 1000 \mu m. We interpret this as a possible tidal breakup of an exo-asteroid by the WD .
Further follow-up observations of this rare event may provide insights on the origin of dust disk and metal pollution in some white dwarfs .