Planet-disk interactions in HD 169142? Tracing ellipticity, structures, and offsets

In Bertrang et al. (2018), we present new data of the protoplanetary disk surrounding the Herbig Ae/Be star HD 169142 obtained in the very broad-band (VBB) with the Zurich imaging polarimeter (ZIMPOL), a subsystem of the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) at the Very Large Telescope (VLT). Our Polarimetric Differential Imaging (PDI) observations probe the disk as close as 0.″3 (3.5au) to the star and are able to trace the disk out to ~1.″08 (~126 au). We find an inner hole, a bright ring bearing substructures around ~0.″18 (21au), and an elliptically shaped gap stretching from 0.″25 to 0.″47 (29-55 au). Outside of 0.″47, the surface brightness drops off, discontinued only by a narrow annular brightness minimum at ~0.″63-0.″74 (74-87 au). These observations confirm features found in less-well resolved data as well as reveal yet undetected indications for planet-disk interactions, such as small-scale structures, star-disk offsets, and potentially moving shadows.