HD 104860 and HD 192758: Two Debris Disks Newly Imaged in Scattered Light with the Hubble Space Telescope
- 10 February 2018
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 854 (1), 53
- https://doi.org/10.3847/1538-4357/aaa892
Abstract
We present the first scattered-light images of two debris disks around the F8 star HD 104860 and the F0V star HD 192758, respectively ~45 and ~67 pc away. We detected these systems in the F110W and F160W filters through our reanalysis of archival Hubble Space Telescope (HST) NICMOS data with modern starlight-subtraction techniques. Our image of HD 104860 confirms the morphology previously observed by Herschel in thermal emission with a well-defined ring at a radius of ~114 au inclined by ~58°. Although the outer edge profile is consistent with dynamical evolution models, the sharp inner edge suggests sculpting by unseen perturbers. Our images of HD 192758 reveal a disk at radius ~95 au inclined by ~59°, never resolved so far. These disks have low scattering albedos of 10% and 13%, respectively, inconsistent with water ice grain compositions. They are reminiscent of several other disks with similar inclination and scattering albedos: Fomalhaut, HD 92945, HD 202628, and HD 207129. They are also very distinct from brighter disks in the same inclination bin, which point to different compositions between these two populations. Varying scattering albedo values can be explained by different grain porosities, chemical compositions, or grain size distributions, which may indicate distinct formation mechanisms or dynamical processes at work in these systems. Finally, these faint disks with large infrared excesses may be representative of an underlying population of systems with low albedo values. Searches with more sensitive instruments on HST or on the James Webb Space Telescope and using state-of-the art starlight-subtraction methods may help discover more of such faint systems.Keywords
This publication has 85 references indexed in Scilit:
- MODELING COLLISIONAL CASCADES IN DEBRIS DISKS: STEEP DUST-SIZE DISTRIBUTIONSThe Astrophysical Journal, 2012
- HUBBLE SPACE TELESCOPEOBSERVATIONS OF THE HD 202628 DEBRIS DISKThe Astronomical Journal, 2012
- SELF-CONSISTENT SIZE AND VELOCITY DISTRIBUTIONS OF COLLISIONAL CASCADESThe Astrophysical Journal, 2012
- STRUCTURE AND EVOLUTION OF DEBRIS DISKS AROUND F-TYPE STARS. I. OBSERVATIONS, DATABASE, AND BASIC EVOLUTIONARY ASPECTSThe Astrophysical Journal Supplement Series, 2011
- Vertical structure of debris discsAstronomy & Astrophysics, 2009
- A New Algorithm for Point‐Spread Function Subtraction in High‐Contrast Imaging: A Demonstration with Angular Differential ImagingThe Astrophysical Journal, 2007
- Discovery of an 86 AU Radius Debris Ring around HD 181327The Astrophysical Journal, 2006
- Dust Dynamics, Surface Brightness Profiles, and Thermal Spectra of Debris Disks: The Case of AU MicroscopiiThe Astrophysical Journal, 2006
- Angular Differential Imaging: A Powerful High‐Contrast Imaging TechniqueThe Astrophysical Journal, 2006
- Diffuse radiation in the GalaxyThe Astrophysical Journal, 1941