References to the optical identifications, finding charts and other relevant data for the sources observed can be found in Jauncey et al. (1993). Notes on individual objects are given in Sect. 4.
The observations were carried out with the Maksutov astrograph (field:
, scale: 100
/mm) at the Estación Astronómica de
Cerro el Roble, operated by the University of Chile. Details on the observational and reduction procedure can
be found in Costa & Loyola
(1992, 1994 and 1996; hereafter Papers I, II and III, respectively).