Research on Supermassive binary black hole in OJ 287

Tuorla Observatory has a special relationship with one particular AGN, OJ 287. It is one of the targets of the combined optical and radio monitoring program of Tuorla Observatory and Metsähovi Radio Observatory. Combining this data with archival data, researchers at Tuorla discovered that OJ 287 brightened periodically in the optical wavelengths, with a period of approximately 12 years (Sillanpää et al. 1988). This discovery led to the publication of a supermassive binary black hole model for OJ 287. From this time onwards, OJ 287 has been intensively studied at Tuorla with a variety of approaches including Post-Newtonian black hole dynamics modelling, accretion disk research, comprehensive time series analysis, multifrequency and polarization studies, etc. If any single AGN could be nominated as the official Tuorla mascot, it would without question be OJ 287.



Figure 1: A binary black hole model for OJ 287. (credit S&T: Gregg Dinderman)

Selected publications:


Working groups

X-ray binaries

Description of the group activity.
Group meetings take place on Wednesdays (first and third of each month), 15.00 in the coffee room.

Stellar explosions

Description of the group activity.
Group meetings take place on Mondays, 15.00 in the coffee room.

AGNs and Very High Energy Astrophysics

Description of the group activity.
Group meetings take place on Wednesday (second and fourth of each month), 15.00 in the coffee room.