The optically and IR-bright and starlight-scattering HR 4796A ringlike debris disk is one of the most-(and best-) studied exoplanetary debris systems. The presence of a yet-undetected planet has been inferred (or suggested) from the narrow width and inner/outer truncation radii of its r = 1.'' 05 (77 au) debris ring. We present new, highly sensitive Hubble Space Telescope (HST) visible-light images of the HR 4796A circumstellar debris system and its environment over a very wide range of stellocentric angles from 0.'' 32 (23 au) to approximate to 15 '' (1100 au). These very high-contrast images were obtained with the Space Telescope Imaging Spectrograph (STIS) using six-roll PSF template-subtracted coronagraphy suppressing the primary light of HR 4796A, with three image-plane occulters, and simultaneously subtracting the background light from its close angular proximity M2.5V companion. The resulting images unambiguously reveal the debris ring embedded within a much larger, morphologically complex, and biaxially asymmetric exo-ring scattering structure. These images at visible wavelengths are sensitive to and map the spatial distribution, brightness, and radial surface density of micron-size particles over 5 dex in surface brightness. These particles in the exo-ring environment may be unbound from the system and interacting with the local ISM. Herein, we present a new morphological and photometric view of the larger-than-prior-seen HR 4796A exoplanetary debris system with sensitivity to small particles at stellocentric distances an order of magnitude greater than has previously been observed.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/626527 |
| Date | 22 January 2018 |
| Creators | Schneider, Glenn, Debes, John H., Grady, Carol A., Gáspár, Andras, Henning, Thomas, Hines, Dean C., Kuchner, Marc J., Perrin, Marshall, Wisniewski, John P. |
| Contributors | Univ Arizona, Steward Observ, Univ Arizona, Dept Astron |
| Publisher | IOP PUBLISHING LTD |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Article |
| Rights | © 2018. The American Astronomical Society. All rights reserved. |
| Relation | http://stacks.iop.org/1538-3881/155/i=2/a=77?key=crossref.3e5df83c49ffe13f309a9173ff46526a |
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