HST/NICMOS2 observations of the HD 141569 A circumstellar disk

Abstract

We report the first resolved scattered light images of the circumstellar dust disk around the old Pre-Main Sequence star da. The disk seen in HST/NICMOS2 images shapes a bright annulus inclined at 37.5degr +/- 4.5degr from edge-on. This ring peaks at 325+/-10 AU from the star with a characteristic width of ~ 150 AU. At 1.6 mu m, the dust grains scatter a total flux density of at least 4.5+/- 0.5 mJy. Our disk model using the spatial distribution implied by the images does not explain the 10 mu m excess and requires an additional grain population closer to the star. Some similarities and differences with the dust annulus surrounding HR 4796 A are pointed out. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract No. NAS5-26555.