The Disk Around CoKu Tauri/4: Circumbinary, Not Transitional
Abstract
CoKu Tau/4 has been labeled as one of the very few known transition disk objects—disks around young stars that have their inner disks cleared of dust, arguably as a result of planetary formation. We report aperture-masking interferometry and adaptive optics imaging observations showing that CoKu Tau/4 is in fact a near-equal binary star of projected separation ~53 mas (~8 AU). The spectral energy distribution of the disk is then naturally explained by the inner truncation of the disk through gravitational interactions with the binary star system. We discuss the possibility that such "unseen" binary companions could cause other circumbinary disks to be labeled as transitional.
Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2008
- DOI:
- 10.1086/588216
- arXiv:
- arXiv:0803.2044
- Bibcode:
- 2008ApJ...678L..59I
- Keywords:
-
- stars: low-mass;
- brown dwarfs;
- Astrophysics
- E-Print:
- 5 pages, 3 figures, accepted for ApJL