The asymmetric dust environment of IK Tauri

Mid-infrared observations of IK Tau have been made at 11.15 mu m with the three-telescope Infrared Spatial Interferometer on Mount Wilson and also using individual segments of the Keck telescope for multiple-aperture interferometry on the Keck telescope at 10.7 mu m. Both experiments provided closure phase and show temporal variations and asymmetries in the surrounding dust, with a difference of about 15% in intensity between two sides of the star. Asymmetries have been previously observed in the distribution of SiO masers closely surrounding the star. Comparison with earlier interferometric measurements shows substantial reduction in dust surrounding the star over the last decade. Several asymmetric dust models are investigated and simple images constructed.