PKS 0521-365 is an active galactic nucleus in the southern constellation of Columba.
Because of its proximity, the source (BL Lac object) is a strong emitter from radio to gamma frequencies.
[2] This object first came of interest when an optical counterpart of a radio source was identified.
Photometric study showed the source varied in brightness by up to a magnitude over monthly periods.
The spectrum is nearly continuous with only weak emission lines, suggesting this is a BL Lac object.