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Session 90 - OJ287 and X-Ray Emission from Elliptical Galaxies.
Oral session, Wednesday, January 15
The quasar OJ287 has a light curve extending over one hundred years since it has been photographed accidentally since 1893. In recent years systematic monitoring has been carried out e.g.\ by the large monitoring campaign OJ-94, which was set up to check whether the quasar brightens above the usual brightness level in 1994 as it has done regularly at 12 yr intervals at least since 1910^1. The large outburst in 1994 came as expected. A detailed analysis of the light curve lead to a binary black hole model which predicts all future outbursts with the expected accuracy of one week^2. The first prediction of the new model was a second outburst between November 1995 and January 1996. The outburst came in time thus confirming the expectations of the binary black hole model. The next predicted outburst in the first half of 1996 has also taken place^3. Because of the strong gravitational fields involved in the supermassive binary black hole model, the timing of future outbursts will provide a sensitive test of the general theory of relativity in very strong gravitational fields, exceeding by a factor 10^4 the gravitational fields present in the binary pulsar PSR 1913+16. ^1 Sillanpää, A., Haarala, S., Valtonen, M.J., Sundelius, B. amp; Byrd, G.G. 1988, ApJ, 325, 628 ^2 Lehto, H.J. amp; Valtonen, M.J. 1996, ApJ, 460, 207 ^3 Sundelius, B., Wahde, M., Lehto, H.J. amp; Valtonen, M.J. 1996 in Workshop on blazar variability, Eds. H.R. Miller amp; J.R. Webb
Program listing for Wednesday