Ritter A. and Parker Q.A., A Preferred Orientation Angle for Bipolar Planetary Nebulae., WorkPLANS II. Basel, Switzerland, MDPI Galaxies, 2020, 8, 1-6.
Publication No. : 309989; Weighting : 1.0000
We present preliminary results from measuring Galactic orientation angles of 766 elliptical and bipolar Planetary Nebulae (PNe) in the Hong Kong/Australian Astronomical Observatory/Strasbourg Observatory H-alpha Planetary Nebula research platform and database (HASH DB). For elliptical PNe the distribution of orientation angles is found to be more or less uniform. However, for bipolar PNe there is statistically significant evidence for preferred orientation angles (as tentatively reported before with smaller samples) across the whole Galaxy.