Images of OH231 in optical light (left) and ¹²CO (right) taken from the literature. Left: an overlay of optical and near-IR images of OH231 obtained from the Hubble Legacy Archive. North is up. The white circle provides an image scale. Right: spatial distribution and axial Doppler speeds of ¹²CO lines from OH231 obtained at the Plateau de Bure interferometer and republished with permission (CO panel source: a Web document entitled “From the AGB to the PN phase with the Plateau de Bure Interferometer“ posted as a PDF file by A. Castro-Carrizo with J.M. Winters and R. Neri, c. 1998, with no public URL. These CO results were subsequently reformatted and republished by A+01). The upper (lower) row shows the images and kinematic results for the ¹²CO(1–0) (¹²CO(2–1)) line.