The light curve of PKS 1302−102 appears to be sinusoidal with an amplitude of 0.14 mag and a period of 1,884 ± 88 days, which suggests evidence of a supermassive black hole binary.
[4] PKS 1302−102 was selected from the Catalina Real-Time Transient Survey as one of 20 quasars with apparent periodic variations in the light curve.
Of these quasars, PKS 1302−102 appeared to be the best candidate in terms of sinusoidal behavior and other selection criteria, such as data coverage of more than 1.5 cycles in the measured period.
[4] One plausible interpretation of the apparent periodic behavior is the possibility of two supermassive black holes (SMBH) orbiting each other with a separation of approximately 0.1 pc in the final stages of a 3.3 billion year old galaxy merger.
[5] Further observations of the quasar could either promote true periodicity or rule out a binary interpretation, especially if the measured light curve randomly diverges from the sinusoidal model.