Subtraction of the Achernar reconstructed between different epochs. From left to right, subtraction between the 2012 and 2011 images, subtraction between the 2014 and 2011 images, and subtraction between the 2014 and 2011 images. East is left and north is up. The long arrow shows the previously estimated position angle of the rotation axis of the star on the plane of sky. The green ellipse indicates the delimiting profile of the RvZ model of the photosphere model of Achernar, and the images are highlighted with contours −0.02, −0.01, 0.01, and 0.02.