Bin Ren, Johns Hopkins University
Élodie Choquet, Laboratoire d'Astrophysique de Marseille
Marshall D. Perrin, Space Telescope Science Institute
Gaspard Duchěne, University of California, Berkeley
John H. Debes, Space Telescope Science Institute
Laurent Pueyo, Space Telescope Science Institute
Malena Rice, Yale University
Christine Chen, Johns Hopkins University
Glenn Schneider, The University of Arizona
Thomas M. Esposito, University of California, Berkeley
Charles A. Poteet, Space Telescope Science Institute
Jason J. Wang, California Institute of Technology
S. Mark Ammons, Lawrence Livermore National Laboratory
Megan Ansdell, University of California, Berkeley
Pauline Arriaga, University of California, Los Angeles
Vanessa P. Bailey, Jet Propulsion Laboratory
Travis Barman, The University of Arizona
Juan Sebastián Bruzzone, Western University
Joanna Bulger, National Institutes of Natural Sciences - National Astronomical Observatory of Japan
Jeffrey Chilcote, University of Notre Dame
Tara Cotten, University of Georgia
Robert J. De Rosa, University of California, Berkeley
Rene Doyon, Institut de Recherche sur les Exoplanètes
Michael P. Fitzgerald, University of California, Los Angeles
Katherine B. Follette, Amherst College
Stephen J. Goodsell, Gemini Observatory
Benjamin L. Gerard, University of Victoria
James R. Graham, University of California, Berkeley
Alexandra Z. Greenbaum, University of Michigan, Ann Arbor
J. Brendan Hagan, Space Telescope Science Institute
Pascale Hibon, Gemini ObservatorySouthern Operations Center
Dean C. Hines, Space Telescope Science Institute
Kimberly Ward-Duong, Amherst CollegeFollow
et al, Various Institutions

Document Type


Publication Date


Publication Title

Astrophysical Journal


We have obtained Hubble Space Telescope STIS and NICMOS and Gemini/GPI scattered-light images of the HD 191089 debris disk. We identify two spatial components: a ring resembling the Kuiper Belt in radial extent (FWHM ∼ 25 au, centered at ∼46 au) and a halo extending to ∼640 au. We find that the halo is significantly bluer than the ring, consistent with the scenario that the ring serves as the "birth ring" for the smaller dust in the halo. We measure the scattering phase functions in the 30°-150° scattering-angle range and find that the halo dust is more forward- and backward-scattering than the ring dust. We measure a surface density power-law index of -0.68 ± 0.04 for the halo, which indicates the slowdown of the radial outward motion of the dust. Using radiative transfer modeling, we attempt to simultaneously reproduce the (visible) total and (near-infrared) polarized intensity images of the birth ring. Our modeling leads to mutually inconsistent results, indicating that more complex models, such as the inclusion of more realistic aggregate particles, are needed.


protoplanetary disks, radiative transfer, stars: imaging, stars: individual (HD 191089), techniques: image processing










© 2019. The American Astronomical Society.


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