Imaging an 80 au Radius Dust Ring around the F5V Star HD 157587

Maxwell A. Millar-Blanchaer , Jason J. Wang , Paul Kalas , James R. Graham , Gaspard Duchêne (1) , Eric L. Nielsen , Marshall Perrin , Dae-Sik Moon , Deborah Padgett , Stanimir Metchev , S. Mark Ammons , Vanessa P. Bailey , Travis Barman , Sebastian Bruzzone , Joanna Bulger , Christine H. Chen , Jeffrey Chilcote , Tara Cotten , Robert J. de Rosa , Rene Doyon , Zachary H. Draper , Thomas M. Esposito , Michael P. Fitzgerald , Katherine B. Follette , Benjamin L. Gerard , Alexandra Z. Greenbaum , Pascale Hibon , Sasha Hinkley , Li-Wei Hung , Patrick Ingraham , Mara Johnson-Groh , Quinn Konopacky , James E. Larkin , Bruce Macintosh , Jérôme Maire , Franck Marchis , Mark S. Marley , Christian Marois , Brenda C. Matthews , Rebecca Oppenheimer , David Palmer , Jennifer Patience , Lisa Poyneer , Laurent Pueyo , Abhijith Rajan , Julien Rameau , Fredrik T. Rantakyrö , Dmitry Savransky , Adam C. Schneider , Anand Sivaramakrishnan , Inseok Song , Remi Soummer , Sandrine Thomas , David Vega , J. Kent Wallace , Kimberly Ward-Duong , Sloane Wiktorowicz , Schuyler Wolff

1 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble

We present H-band near-infrared polarimetric imaging observations of the F5V star HD 157587 obtained with the Gemini Planet Imager (GPI) that reveal the debris disk as a bright ring structure at a separation of ∼80-100 au. The new GPI data complement recent Hubble Space Telescope/STIS observations that show the disk extending out to over 500 au. The GPI image displays a strong asymmetry along the projected minor axis as well as a fainter asymmetry along the projected major axis. We associate the minor and major axis asymmetries with polarized forward scattering and a possible stellocentric offset, respectively. To constrain the disk geometry, we fit two separate disk models to the polarized image, each using a different scattering phase function. Both models favor a disk inclination of ∼70° and a 1.5 ± 0.6 au stellar offset in the plane of the sky along the projected major axis of the disk. We find that the stellar offset in the disk plane, perpendicular to the projected major axis is degenerate with the form of the scattering phase function and remains poorly constrained. The disk is not recovered in total intensity due in part to strong adaptive optics residuals, but we recover three point sources. Considering the system’s proximity to the galactic plane and the point sources’ positions relative to the disk, we consider it likely that they are background objects and unrelated to the disk’s offset from the star.

Mots clés: planet–disk interactions; stars: individual: HD 157587; techniques: polarimetric; Astrophysics - Earth and Planetary Astrophysics

Domaines: Planète et Univers [physics]

Maxwell A. Millar-Blanchaer, Jason J. Wang, Paul Kalas, James R. Graham, Gaspard Duchêne, et al.. Imaging an 80 au Radius Dust Ring around the F5V Star HD 157587. The Astronomical Journal, 2016, 152, ⟨10.3847/0004-6256/152/5/128⟩. ⟨insu-03691483⟩