c © ESO 2014 Astronomy &Astrophysics Letter to the Editor

We have mapped the 12CO(3–2) line emission around the Mira AB system at 0.′′5 resolution using the Atacama Large Millimeter/submillimeter Array (ALMA). The CO map shows amazing complexity. The circumstellar gas has been shaped by dif-ferent dynamical actors during the evolution of the system, and several morphological components can be identified. The companion is marginally resolved in continuum emission and is currently at 0.′′487 ± 0.′′006 separation. In the main line component, centered on the stellar velocity, spiral arcs around Mira A are found. The spiral appears to be relatively flat and oriented in the orbital plane. An accretion wake behind the companion is clearly visible, and the projected arc separation is about 5′′. In the blue wing of th