%0 Journal Article %T The Drop during Less than 300 days of a Dusty White Dwarf's Infrared Luminosity %A S. Xu %A M. Jura %J Physics %D 2014 %I arXiv %R 10.1088/2041-8205/792/2/L39 %X We report Spitzer/IRAC photometry of WD J0959-0200, a white dwarf that displays excess infrared radiation from a disk, likely produced by a tidally disrupted planetesimal. We find that in 2010, the fluxes in both 3.6 $\mu$m and 4.5 $\mu$m decreased ~ 35% in less than 300 days. The drop in the infrared luminosity is likely due to an increase of the inner disk radius from one of two scenarios: (i) a recent planetesimal impact; (ii) instability in the circumstellar disk. The current situation is tantalizing; high sensitivity, high cadence infrared studies will be a new tool to study the interplay between a disk and its host white dwarf star. %U http://arxiv.org/abs/1408.1618v1