Imaging faint brown dwarf companions close to bright stars with a small, well-corrected telescope aperture
Abstract
We have used our 1.6 m diameter off-axis well-corrected subaperture (WCS) on the Palomar Hale telescope in concert with a small inner-working-angle phase-mask coronagraph to image the immediate environs of a small number of nearby stars. Test cases included three stars (HD 130948, HD 49197, and HR7672) with known brown dwarf companions at small separations, all of which were detected. We also present the initial detection of a new object close to the nearby young G0V star HD171488. Follow-up observations are needed to determine if this object is a bona fide companion, but its flux is consistent with the flux of a young brown dwarf or low-mass M star at the same distance as the primary. Interestingly, at small angles our WCS coronagraph demonstrates a limiting detectable contrast comparable to that of extant Lyot coronagraphs on much larger telescopes corrected with current-generation adaptive optics (AO) systems. This suggests that small apertures corrected to extreme AO (ExAO) levels can be used to carry out initial surveys for close brown dwarf and stellar companions, leaving follow-up observations for larger telescopes.
Additional Information
© 2009 The American Astronomical Society. Received 2008 September 27; accepted 2009 January 27; published 2009 April 13. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration, and is based in part on observations obtained at the Hale Telescope, Palomar Observatory, as part of a continuing collaboration between the California Institute of Technology, NASA/JPL, and Cornell University. We thank M. Troy and the JPLAO team, and the staff of the Palomar Observatory for their able and ready assistance. Note added in proof. In a recent paper, Metchev & Hillenbrand (2009) conclude that the faint source near HD171488 is not a bona fide companion.Attached Files
Published - Serabyn2009p2252Astrophys_J.pdf
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Additional details
- Eprint ID
- 14353
- Resolver ID
- CaltechAUTHORS:20090602-153032700
- NASA/JPL/Caltech
- Created
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2009-08-27Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field