2724 20160706140826.0 ASTROimport-881 Aleman, I. 2015 The Herschel Planetary Nebula Survey (HerPlaNS) is an imaging and spectroscopy survey of 11 planetary nebulae (PNe) in the far-IR using the PACS and SPIRE instruments aboard the Herschel Space Observatory. A line survey in these PNe over the entire spectral range between 51 µm and 672 µm revealed the first detections of OH+ emission in PNe. The rotational emission lines of OH+ at 152.99, 290.20, 308.48, and 329.77 µm were detected in the spectra of three PNe: NGC 6445, NGC6720, and NGC 6781. Excitation temperatures and column densities in the range of 27 - 47 K and 2×1010 - 4×1011 cm-2, respectively, were derived from these lines. In these objects, the OH+ rotational line emission is mostly likely produced in the photodissociation region (PDR). The emission of OH+ is observed only in PNe with hot central stars (Teff > 100000 K), with ring-like or torus-like structure. The fact that we do not detect OH+ in objects with Teff 100000 K suggests that the hardness of the ionizing central star spectra (i.e. the production of soft X-rays, ˜ 100 - 300 eV) could be an important factor in the production of OH+ emission in PNe, as seems to be the case in recent OH+ detections in ultraluminous galaxies and supernovae remnants. Herschel Planetary Nebula Survey (HerPlaNS): First Detection of OH+ in Planetary Nebulae Ueta, T. Ladjal, D. Exter, K. Kastner, J. Montez, R. Tielens, X. Chu, Y.-H. Izumiura, H. McDonald, I. Sahai, R. Siódmiak, N. Szczerba, R. van Hoof, P. A. M. Villaver, E. Vlemmings, W. Wittkowski, M. Zijlstra, A. 108.05 American Astronomical Society Meeting Abstracts 225 2015 http://esoads.eso.org/abs/2015AAS...22510805A published in NONREF