PKS 0736+017 is found violent variable across its electromagnetic spectrum.[7][8] It showed an outburst in December 2001 where its brightness level reached a maximum of 14.90 in the B band, 13.79 in the R band and 14.34 in the V band. The spectral slope remained constant while brightness level showed a sharp decrease by 0.3 magnitude during 4.5 hours.[9]
In 2002, PKS 0736+017 exhibited multiple variability behaviors. During most nights, the quasar was in an optical faint state displaying fluctuations on a small-scale. When observed during three nights, it became more variable and brighter. In its active state, PKS 0736+017 showed a rapid flare followed by quasi-periodic low-amplitude variations. Accompanied by the flare, were complex oscillations that soon continued and clearly shown once the quasar reached its high state. One week later, another flare was observed although not rapid as the first.[3] During the quasar's brighten state, its color variation became redder.[10]
The optical domain of PKS 0736+017 shows strong forbidden and permitted emission lines.[9] Not to mention, its broad hydrogen emission lines are known to show significant disparities. Between 1978 and 1980, the H-beta line intensity in PKS 0736+017 decreased by 40 percent, with it increasing by 50 percent between 1985 and 1986. As for its H-gamma line intensity, a large fractional change is seen.[14] In additional, its visible spectrum is found identical to 3C 273, which both quasars have iron, hydrogen and helium permitted lines but no forbidden lines.[15]
^Cerruti, Matteo; Lenain, Jean-Philippe; Prokoph, Heike (2017-08-16). "H.E.S.S. Discovery of very-high-energy emission from the blazar PKS 0736+017: On the location of the γ-ray emitting region in FSRQS". Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017). Trieste, Italy: Sissa Medialab. p. 627. doi:10.22323/1.301.0627.