@article{3069664,
    title = "Primary black hole spin in oj 287 AS determined by the general relativity centenary flare",
    author = "Valtonen, M.J. and Zola, S. and Ciprini, S. and Gopakumar, A. and Matsumoto, K. and Sadakane, K. and Kidger, M. and Gazeas, K. and Nilsson, K. and Berdyugin, A. and Piirola, V. and Jermak, H. and Baliyan, K.S. and Alicavus, F. and Boyd, D. and Torrent, M.C. and Campos, F. and Gómez, J.C. and Caton, D.B. and Chavushyan, V. and Dalessio, J. and Debski, B. and Dimitrov, D. and Drozdz, M. and Er, H. and Erdem, A. and Pérez, A.E. and Ramazani, V.F. and Filippenko, A.V. and Ganesh, S. and Garcia, F. and Gómez Pinilla, F. and Gopinathan, M. and Haislip, J.B. and Hudec, R. and Hurst, G. and Ivarsen, K.M. and Jelinek, M. and Joshi, A. and Kagitani, M. and Kaur, N. and Keel, W.C. and Lacluyze, A.P. and Lee, B.C. and Lindfors, E. and Lozano De Haro, J. and Moore, J.P. and Mugrauer, M. and Naves Nogues, R. and Neely, A.W. and Nelson, R.H. and Ogloza, W. and Okano, S. and Pandey, J.C. and Perri, M. and Pihajoki, P. and Poyner, G. and Provencal, J. and Pursimo, T. and Raj, A. and Reichart, D.E. and Reinthal, R. and Sadegi, S. and Sakanoi, T. and Salto González, J.-L. and Sameer and Schweyer, T. and Siwak, M. and Soldán Alfaro, F.C. and Sonbas, E. and Steele, I. and Stocke, J.T. and Strobl, J. and Takalo, L.O. and Tomov, T. and Tremosa Espasa, L. and Valdes, J.R. and Valero Pérez, J. and Verrecchia, F. and Webb, J.R. and Yoneda, M. and Zejmo, M. and Zheng, W. and Telting, J. and Saario, J. and Reynolds, T. and Kvammen, A. and Gafton, E. and Karjalainen, R. and Harmanen, J. and Blay, P.",
    journal = "The Astrophysical Journal Letters",
    year = "2016",
    volume = "819",
    number = "2",
    publisher = "INSTITUTE OF PHYSICS PUBLISHING",
    issn = "2041-8205, 2041-8213",
    doi = "10.3847/2041-8205/819/2/L37",
    abstract = "OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in a binary black hole model. The model predicted a major optical outburst in 2015 December. We found that the outburst did occur within the expected time range, peaking on 2015 December 5 at magnitude 12.9 in the optical R-band. Based on Swift/XRT satellite measurements and optical polarization data, we find that it included a major thermal component. Its timing provides an accurate estimate for the spin of the primary black hole, . The present outburst also confirms the established general relativistic properties of the system such as the loss of orbital energy to gravitational radiation at the 2% accuracy level, and it opens up the possibility of testing the black hole no-hair theorem with 10% accuracy during the present decade. © 2016. The American Astronomical Society. All rights reserved."
}