The white dwarf Giclas 29-38 has attracted much attention due to its large infrared excess and the suggestion that excess might be due to a companion brown dwarf .
We observed this object using speckle interferometry at the Keck telescope , obtaining diffraction-limited resolution ( 55 milliarcseconds ) at K band , and found it unresolved .
Assuming the entire K band excess is due to a single point-like companion , we place an upper limit on the binary separation of 30 milliarcseconds , or 0.42 AU at the star ’ s distance of 14.1 pc .
This result , combined with astroseismological data and other images of G29-38 , supports the hypothesis that the source of the near-infrared excess is not a cool companion but a dust cloud .