416 citations
- Kyoto UniversityJP49 papers
- National Astronomical Observatory of JapanJP44 papers
- Crimean Astrophysical ObservatoryUA30 papers
- British Astronomical AssociationGB24 papers
- Vihorlat ObservatorySK22 papers
- Nordic Optical TelescopeES21 papers
- American Association of Variable Star ObserversUS20 papers
- Hiroshima UniversityJP20 papers
- The University of TokyoJP19 papers
- University of TurkuFI18 papers
- Kazan Federal UniversityRU17 papers
- Lomonosov Moscow State UniversityRU17 papers
5 papers · 2 filters
On the need of an ultramassive black hole in OJ 287
Mauri J. Valtonen, Staszek Zola, Achamveedu Gopakumar +25
The highly variable blazar OJ~287 is commonly discussed as an example of a binary black hole system. The 130 year long optical light curve is well explained by a model where the ce…
Observational Implications of OJ 287's Predicted 2022 Disk Impact in the Black Hole Binary Model
Mauri J. Valtonen, Lankeswar Dey, Achamveedu Gopakumar +24
We present a summary of the results of the OJ 287 observational campaign, which was carried out during the 2021/2022 observational season. This season is special in the binary mode…
Refining the 2022 OJ 287 impact flare arrival epoch
Mauri J. Valtonen, Staszek Zola, Gopakumar +24
The bright blazar OJ~287 routinely parades high brightness bremsstrahlung flares, which are explained as being a result of a secondary supermassive black hole (SMBH) impacting the…
The optical behaviour of BL Lacertae at its maximum brightness levels: a blend of geometry and energetics
C. M. Raiteri, M. Villata, S. G. Jorstad +13
In 2021 BL Lacertae underwent an extraordinary activity phase, which was intensively followed by the Whole Earth Blazar Telescope (WEBT) Collaboration. We present the WEBT optical…
Catching profound optical flares in blazars
Gopal Bhatta, Staszek Zola, M. Drozdz +11
Flaring episodes in blazars represent one of the most violent processes observed in extra-galactic objects. Studies of such events shed light on the energetics of the physical proc…