2005ApJ...635L.161R

We present new observations of the white dwarf G29-38 with the camera (4.5 and 8 µm), photometer (24 µm), and spectrograph (5.5-14 µm) of the Spitzer Space Telescope. This star has an exceptionally large infrared excess, amounting to 3% of the bolometric luminosity. The spectral energy distribution (SED) has a continuum peak around 4.5 µm and a 9-11 µm emission feature 1.25 times brighter than the continuum. A mixture of amorphous olivine and a small amount of forsterite in an emitting region 1-5 R_☉from the star can reproduce the shape of the 9-11 µm feature. The SED also appears to require amorphous carbon to explain the hot continuum. Our new measurements support the idea that a relatively recent disruption of a comet or asteroid created the cloud.