Article: Millar-Blanchaer, MA; Wang, JJ; Kalas, P; Graham, JR; Duchene, G; Nielsen, EL; Perrin, M; Moon, DS; Padgett, D; Metchev, S; Ammons, SM; Bailey, VP; Barman, T; Bruzzone, S; Bulger, J; Chen, CH; Chilcote, J; Cotten, T; De Rosa, RJ; Doyon, R; Draper, ZH; Esposito, TM; Fitzgerald, MP; Follette, KB; Gerard, BL; Greenbaum, AZ; Hibon, P; Hinkley, S; Hung, LW; Ingraham, P; Johnson-Groh, M; Konopacky, Q; Larkin, JE; Macintosh, B; Maire, J; Marchis, F; Marley, MS; Marois, C; Matthews, BC; Oppenheimer, R; Palmer, D; Patience, J; Poyneer, L; Pueyo, L; Rajan, A; Rameau, J; Rantakyro, FT; Savransky, D; Schneider, AC; Sivaramakrishnan, A; Song, I; Soummer, R; Thomas, S; Vega, D; Wallace, JK; Ward-Duong, K; Wiktorowicz, S; Wolff, S; “Imaging an 80 au Radius Dust Ring Around the F5V Star HD 157587”, Astronomical Journal, 152 (5)
Abstract: 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 similar to 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 similar to 70 degrees 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.
Funding Acknowledgement: NASA’s NEXSS program [NNX15AD95G]; U.S. Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344]; NSF [AST-1413718, AST-1518332]; NASA [NNX15AC89G]; Office of Science of the U.S. Department of Energy [DE-AC02-05CH11231]
Funding Text: This work was supported in part by NASA’s NEXSS program, grant number NNX15AD95G. Portions of this work were performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Portions of this work were also carried out with the support of NSF grants AST-1413718 and AST-1518332, and NASA grant NNX15AC89G. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.