Binary α Cen AB as it appears in the sky on various occasions. Shown is the orbit of α Cen B with respect to the primary A, which is at the origin, and with north up and east to the left. During the observing period, the separation of the stars was greatest in 2005 and smallest in 2011. The relative positions in the PACS (blue) and LABOCA (red) maps are indicated. The proper motion of α Cen for the time span between the LABOCA and PACS observations is shown by the dashed arrow. The separation between the stars at the time of the MIPS observations is indicated by the green dot. Orbital elements are adopted from Pourbaix et al. (2002).