Mid‐Infrared Images of the Debris Disk around HD 141569

Abstract

We have imaged the circumstellar debris disk around the A0 Ve/B9.5Ve star HD 141569 (D=99 pc), at λ=12.5, 17.9, and 20.8 μm using theKeck II telescope, and confirm the general morphology from otherrecently published mid-infrared observations. Model fits to an assumedflat radially symmetric dust disk yield an inclination i=53deg+/-5degand a position angle of -6deg+/-4deg for the tilt axis and indicatethe presence of a depression in optical depth by a factor of about4 within a radial distance of 30 AU (0.3") from the star. Such adepression is suggestive of a density depletion and is consistentwith published spectral energy distributions that indicate the absenceof a near-infrared excess even though a mid-infrared excess is present.Our mid-infrared results, in conjunction with previously publishednear-infrared scattering images, suggest that the two wavelengthregimes are viewing, respectively, the inner and outer parts of acommon disk structure, which is dominated by small (probably submicron)grains throughout.