A Spitzer White Dwarf Infrared Survey
  We present mid-infrared photometry of 124 white dwarf stars with Spitzer Space Telescope. Objects were observed simultaneously at 4.5 and 8.0um with sensitivities better than 1 mJy. This data can be used to test models of white dwarf atmospheres in a new wavelength regime, as well as to search for planetary companions and debris disks. 
F. Mullally, Mukremin Kilic, William T. Reach, Marc J. Kuchner, Ted   von Hippel, Adam Burrows and D. E. Winget