Correlated ground based observations in support of the HEAO-1 X-ray observatory

Using X-ray and optical photometry of UBVRI fluxes, energetic compact extragalactic sources were studied, such as BL Lacerta (Lac) and BL Lac objects-Markarian (Mrk) 421, Mrk 501, and B2 1308+32. BL Lac and BL Lac objects were found to have predominantly nonthermal spectrums. Photometric and spectroscopic properties of X Persei, an unusual Be star associated with an intrinsically weak X-ray source, were also studied. Both its X-ray and optical emission show complex variability on many different time scales.