Weight map of a DIRBE healpixel. This represents the probability for a star to contribute to the healpixel flux as a function of its position in the sky. The diamond shape represents the particular healpixel (here in the Taurus-Perseus region). The thick pillow-like contour delimits the region inside which all stars contribute in all individual observations (probability = 1). The dashed circles represent the probability = 1 for a star to contribute for the given pointing. Each of the four circles is centered on one of the four corners of the diamond shape. The outer thick circle is the probability = 0.5 for a star to contribute.