Direct Detection of Planets Orbiting Large Angular Diameter Stars: Sensitivity of an Internally Occulting Space-based Coronagraph
- Creators
- Crepp, Justin R.
- Mahadevan, Suvrath
- Ge, Jian
Abstract
High-contrast imaging observations of large angular diameter stars enable complementary science questions to be addressed compared to the baseline goals of proposed missions like the Terrestrial Planet Finder-Coronagraph, New World's Observer, and others. Such targets, however, present a practical problem in that finite stellar size results in unwanted starlight reaching the detector, which degrades contrast. In this paper, we quantify the sensitivity, in terms of contrast, of an internally occulting, space-based coronagraph as a function of stellar angular diameter, from unresolved dwarfs to the largest evolved stars. Our calculations show that an assortment of band-limited image masks can accommodate a diverse set of observations to help maximize mission scientific return. We discuss two applications based on the results: the spectro-photometric study of planets already discovered with the radial velocity technique to orbit evolved stars, which we elucidate with the example of Pollux b, and the direct detection of planets orbiting our closest neighbor, α Centauri, whose primary component is on the main sequence but subtends an appreciable angle on the sky. It is recommended that similar trade studies be performed with other promising internal, external, and hybrid occulter designs for comparison, as there is relevance to a host of interesting topics in planetary science and related fields.
Additional Information
© 2009. The American Astronomical Society. Received 2009 April 9; accepted 2009 June 30; published 2009 August 14. We thank Stuart Shaklan and Amir Give'on for helpful comments regarding an earlier draft of this manuscript and implementation of the electric field conjugation algorithm. We are also grateful for suggestions made by the referee that lead to improved presentation of our results. This work was supported by the UCF-UF SRI program and NASA grant NNG06GC49G.Attached Files
Published - Crepp2009p5894Astrophys_J.pdf
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Additional details
- Eprint ID
- 15862
- Resolver ID
- CaltechAUTHORS:20090915-144812116
- University of Central Florida-University of Florida Space Research Initiative (UCF-UF-SRI)
- NNG06GC49G
- NASA
- Created
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2009-09-16Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field