Multiband monitoring of OJ287 in 1993/94

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Session 110 -- Blazars and BL Lacs
Display presentation, Thursday, 12, 1995, 9:20am - 6:30pm

[110.05] Multiband monitoring of OJ287 in 1993/94

M. Kidger (Instituto de Astrof\'\i sica de Canarias), A. Sillanp\"a\"a, L.O. Takalo, T. Pursimo, H. Lehto, E. Valtaoja, K. Nilsson (Tuorla Observatory), H. Ter\"asranta, M. Tornikoski ( Mets\"ahovi Radio Res. St.), J.A. de Diego, J.N. Gonz\'alez-P\'erez, J.-M. Rodr\'\i guez-Espinosa, T. Mahoney (Instituto de Astrof\'\i sica de Canarias), P. Boltwood (Ont. K2S 1N6, Canada), D. Dulzin-Hacyan, E. Benitez (Instituto de Astronom\'\i a-UNAM), G.W. Turner, J.W. Robertson, R.K. Honeycut (Indiana University), Yu.S. Efimov (Crimean Astrophysical Obs.), N. Shakhovskoy, P. A. Charles (Univ.of Oxford), K. J. Schramm, U. Borgeest, J.V. Linde (Hamburg Universit\"at), A. Sadun (Bradley Obs.), R. Grashuis (Capilla Peak Obs.), M. F. Aller, H. D. Aller , P. A. Hughes (Univ.of Michigan)

The OJ-94 international collaboration has been observing the light curve of OJ287 intensely at radio, millimetric, infrared and visible wavelengths. We present a set of light curves for the 1993/94 observing season in 14 different bands from 4.8GHz to U. The monitoring covers an interval from August 1993 to the end of June 1994. The intensity of light curve monitoring varies considerably in the different bands, from $\sim$1400 points in V (an average of 5 per day over the entire observing season) to a few tens in the least sample bands (1-2 per week). The visible and infrared light curves are probably the best ever compiled of an extragalactic object. The visible and near infrared light curves were extremely active during the observing campaign, with a series of flares being seen of up to 2 magnitudes amplitude and duration from 1-6 weeks. During the observing season there was a strongly marked overall trend in the brightness of OJ287 with the brightness increasing steadily by more than one magnitude; both flares and faint epochs were superimposed on this trend. Significant differences are seen in the light curves in other bands though with very little radio variability being observed and a light curve amplitude in the infrared significantly lower than that in the visible. Although the trend to increasing brightness can be seen in both the infrared and the radio, it is at a very much smaller rate, especially in the latter. No radio activity is seen coincident with the optical flares.

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