Hubble Space Telescope ACS Coronagraphic Imaging of the Circumstellar Disk around HD 141569A

Abstract

Multicolor coronagraphic images of the circumstellar disk around HD141569A have been obtained with the Hubble Space Telescope AdvancedCamera for Surveys. The B, V, and I images show that the disk's previouslydescribed multiple-ring structure is actually a continuous distributionof dust with a tightly wound spiral structure. Extending from thedisk are two, more open spiral arms, one of which appears to reachthe nearby binary star HD 141569BC. Diffuse dust is seen up to 1200AU from HD 141569A. Although planets may exist in the inner regionof the disk, tidal interaction with HD 141569BC seems more likelyto be the cause of these phenomena. The disk appears redder thanthe star (B-V=0.21 and V-I=0.25), and its color is spatially uniform.A scattering asymmetry factor of g=0.25-0.35 is derived. The azimuthaldensity distribution is asymmetric, varying by a factor of ~3 atsome radii.