Jones, D.D.JonesBoffin, H. M. J.H. M. J.BoffinMiszalski, B.B.MiszalskiWesson, R.R.WessonCorradi, R. L. M.R. L. M.CorradiTyndall, A. A.A. A.Tyndall2025-12-302025-12-3020141432-0746https://hdl.handle.net/20.500.12740/24002We present a detailed photometric study of the central star system of the planetary nebula Hen 2-11, selected for study because of its low-ionisation filaments and bipolar morphology - traits which have been strongly linked with central star binarity. Photometric monitoring with NTT-EFOSC2 reveals a highly irradiated, double-eclipsing, post-common-envelope system with a period of 0.609 d. Modelling of the lightcurve indicates that the nebular progenitor is extremely hot, while the secondary in the system is probably a K-type main sequence star. The chemical composition of the nebula is analysed, showing Hen 2-11 to be a medium-excitation non-Type I nebula. A simple photoionisation model is constructed determining abundance ratios of C/O andN/O which would be consistent with the common-envelope cutting short the AGB evolution of the nebular progenitor. The detection of a post-common-envelope binary system at the heart of Hen 2-11 further strengthens the link between binary progeny and the formation of axisymmetric planetary nebulae with patterns of low-ionisation filaments, clearly demonstrating their use as morphological indicators of central star binarity.Acceso Abiertobinaries: closebinaries: eclipsingcircumstellar matterISM: abundancesstars: AGB and post-AGBplanetary nebulae: individual: Hen 2-11http://dx.doi.org/10.1051/0004-6361/201322797