blazar

The term blazar is used for quasars with particular observational characteristics, including significant variability and a significant radio signal (radio loud, making it also a radio galaxy). As such, it is one of the terms used for active galaxies. It is thought that a blazar's active galactic nucleus (AGN) powers a jet that happens to be aimed toward us, effectively beaming its electromagnetic radiation to make them especially bright to us despite their distance. The name blazar was given to objects that are both BL Lac objects (or BLLAC or BLL, objects similar to the active galaxy BL Lacertae, which is known by this variable star designation because it was first thought to be a star) and OVV quasars (optically violent variable quasars).