Speckle suppression and companion detection using coherent differential imaging
Abstract
Residual speckles due to aberrations arising from optical errors after the split between the wavefront sensor and the science camera path are the most significant barriers to imaging extrasolar planets. While speckles can be suppressed using the science camera in conjunction with the deformable mirror, this requires knowledge of the phase of the electric field in the focal plane. We describe a method which combines a coronagraph with a simple phase-shifting interferometer to measure and correct speckles in the full focal plane. We demonstrate its initial use on the Stellar Double Coronagraph at the Palomar Observatory. We also describe how the same hardware can be used to distinguish speckles from true companions by measuring the coherence of the optical field in the focal plane. We present results observing the brown dwarf HD49197b with this technique, demonstrating the ability to detect the presence of a companion even when it is buried in the speckle noise, without the use of any standard 'calibration' techniques. We believe this is the first detection of a substellar companion using the coherence properties of light.
Additional Information
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2016 October 4. Received 2016 October 3; in original form 2016 May 20; Editorial Decision 2016 October 3. We are very pleased to acknowledge the Palomar Observatory staff for their support. During the course of this work, MB was supported by a NASA Space Technology Research Fellowship, grant NNX13AN42H. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA).Attached Files
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Additional details
- Eprint ID
- 75206
- Resolver ID
- CaltechAUTHORS:20170317-124308134
- NNX13AN42H
- NASA Space Technology Research Fellowship
- NASA/JPL/Caltech
- Created
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2017-03-17Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field