PN IPHASX J055226.2+323724 in the open cluster M37. Left: co-addition of all observations, with a total exposure time of 3.52 days as described in the text. Hα is mapped to red and [O III] 5007 Å to green. Broadband frames of the stellar field are mapped to red, green, and blue. The height of the frame is 25′. North is up and east to the left. Note the faint nebulosity at the southeastern rim of the cluster. Right: zoomed-in view of the left panel, with the PN central star circled in green.