We have investigated the possibility that the visual companion of the central star of NGC 650 is physically associated with the latter. Using positions, magnitudes and colours from HST images, we conclude that a physical association is unlikely. We note that the companion is itself a close binary, and possibly a triple system. As by-product of this work, the agreement between the Zanstra temperatures (H and He II ) with the spectroscopic temperature, leads to the conclusion that the nebula is optically deep in H and He II ionizing radiation.
© European Southern Observatory (ESO) 1998
Online publication: June 12, 1998