A SYSTEMATIC STUDY OF IRAS SELECTED PROTOPLANETARY NEBULA CANDIDATES .1. SELECTION OF THE SAMPLE AND OBSERVATIONS OF THE SOUTHERN OBJECTS

This paper is the first of a series, in which we report an extensive s tudy of a sample of 62 IRAS selected proto-planetary nebula candidates . In this paper we describe the selection of the sample. For the 42 so uthern sources in the sample we present the results of observations us ing optical and near-infrared photometry, and optical spectroscopy. Ou t of the 42 sources, 26 are associated with an optical counterpart, 12 do not have an optical counterpart, and 4 sources have more than one possible optical counterpart. Spectroscopy is carried out for 18 sourc es. Spectral types are mainly M, G and F. The photometric observations show that nearly all sources in the sample radiate the bulk of their energy in the IRAS infrared. This implies that the sources are surroun ded by a thick dust shell.