HD 169142 in the eyes of ZIMPOL/SPHERE

Abstract

We present new data of the protoplanetary disc 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 disc as close as 0.03 arcsec (3.5 au) to the star and are able to trace the disc out to ∼1.08 arcsec (∼126 au). We find an inner hole, a bright ring bearing substructures around 0.18 arcsec (21 au), and an elliptically shaped gap stretching from 0.25 to 0.47 arcsec (29–55 au). Outside of 0.47 arcsec, the surface brightness drops off, discontinued only by a narrow annular brightness minimum at ∼0.63 to 0.74 arcsec (74–87 au). These observations confirm features found in less-well-resolved data as well as reveal yet undetected indications for planet-disc interactions, such as small-scale structures, star–disc offsets, and potentially moving shadows.