CCD camera brightness monitoring of Q0957 + 561 A, B

The paper presents results of continued monitoring of the twin QSO 0957 + 561 with data obtained with a CCD camera from February 1983 through March 1984. The 0.2 mag increase previously reported to have occurred from January 1982 through January 1983 in the A component was seen to occur during January 1983 through January 1984 in the B component. From an autocorrelation of the CCD data, the time of arrival difference to be is determined to be = 1.03 + or - 0.1 years; the A image precedes the B image. Also presented are data from 123 observations made on seven nights with 11 minute time resolution, with which a search is made for brightness fluctuations on a time scale of days or hours. The two components seem to have been relatively quiescent at the time of the observations; only marginal evidence is found for nightly brightness fluctuations and no evidence for fluctuations on a time scale of hours.

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