Spectroscopy of variable blue stellar objects

It is pointed out that optical variability has been detected in a significant number of the class of optically selected quasars. The present investigation is concerned with the results of a study of the optical variability of objects selected for their ultraviolet excess (UVX) from three fields in the north galactic polar cap and centered on Karteyn Selected Areas 57, 29, and 28. The study of the luminosity fluctuations of quasars and variable stars leads in theory to a better understanding of their astrophysical nature. But it is necessary first to discover them. Attention is given to the establishment of a list of candidate variables discovered among the UVX objects in the three fields, their spectroscopic identifications, and related statistics.