Keck Speckle Imaging of the White Dwarf G29-38: No Brown Dwarf Companion Detected
The white dwarf Giclas 29-38 has attracted much attention on account of 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 mas) at the K band, and found it unresolved. Assuming that the entire K-band excess is attributable to a single pointlike companion, we place an upper limit on the binary separation of 30 mas, 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.
Additional Information© 1998 American Astronomical Society. Received 1998 August 13; accepted 1998 September 18; published 1998 October 12. We thank Eugene Chiang, Chris Clemens, Michelle Creech- Eakman, Peter Goldreich, and Ben Zuckerman for inspiration and helpful discussions. The observations reported here were obtained at the W. M. Keck Observatory, which is operated by the California Association for Research in Astronomy, a scientific partnership among California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. It was made possible by the generous financial support of the W. M. Keck Foundation.
Published - 1538-4357_508_1_L81.pdf