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The F3 main sequence star KIC 8462852 (Boyajian's Star) showed deep (up to 20%) day-long brightness dips of unknown cause during the 4 years of the Kepler mission. A 0.164 mag (16%) dimming between 1890 and 1990 was claimed, based on the analysis of photographic plates from the Harvard Observatory. We have gathered an independent set of historic plates from Sonneberg Observatory, Germany, covering the years 1934 -1995. With 861 magnitudes in B, and 397 magnitudes in V, we find the star to be of constant brightness within 0.03 mag per century (3%). Consistent outcomes are found using by-eye estimates of the best 119 plates. Results are supported by data from Sternberg Observatory, Moscow, which show the star as constant between 1895 and 1995. The previously claimed century-long dimming is inconsistent with our results at the 5σ-level, however the recently reported modest dimming of 3% in the Kepler data is not inconsistent with our data. We find no periodicities or shorter trends within our limits of 5% per 5-year bin, but note a possible dimming event on 24 Oct 1978.

Abstract. We report the final results of the 1997 campaign of photometric observations of the mutual phenomena of the Galilean satellites carried out at observatories in Kazakhstan, Russia, and Ukraine. Our results contribute substantially to the world data bank of such observations and will allow the model of the motion of Galilean satellites to be further refined. To facilitate the use of photometric data, we reduced them by computing the planetocentric rectangular coordinate differences of satellite pairs for a number of instants of time so we deduce the differences for one instant from one observed light curve. It is these reduced data that constitute the principal result of this work. We based our data reduction on the method which we developed in earlier papers (Emel'yanov 1999;Emel'yanov 2000). The accuracy of observations was estimated in the process of reduction. The paper also describes the equipment used.