We have imaged with ISOCAM, at 4.5 and 15 microns, an extended near edge-on
dust disk surrounding the young B5 V star BD +31 643 (first reported in the
visible by Kalas and Jewitt 1997).  We propose follow-up observations at FIR
wavelengths with ISOPHOT in order to determine the total dust mass of the disk,
and the temperature of the larger dust grains. We propose PHT FIR polarimetry
to study the properties and alignment of grains in any associated field. We
also propose CAM CVF spectrometry in order to ascertain, with spatial
resolution across the approximately 1 arcminute radius disk, the contribution
of unidentified infrared band (UIB) emission to the 5 to 17 micron flux.