Spectroscopic observations of faint and misclassified planetary nebulae.

Using low resolution IDS spectra, an attempt is made to clarify the classification of 264 objects which appeared as planetary nebulae in various listings, and were originally included in two lists of Sanduleak (1976): (1) misclassified or doubtfully classified planetary nebulae; and (2) faint, suspected planetary nebulae. The new data show that 67 percent of the objects can be considered as true planetary nebulae, of which 46 percent present low excitation characteristics. The status of the other objects remains quite uncertain, some of them being symbiotic stars (14 percent), or various emission-line objects. In four cases, no positive indication of emission-line objects in the observed areas was found.