Refined reduction of UBV photometry at Hvar

We then classified 59 Be stars into five classes, based on their variability patterns; namely, long-term envelope (LTE), long-term cyclic (LTC), binarity (BIN), rapid low-amplitude (RLA), and long-term quiescence (LTQ). According to our observations, the percentages of stars in the individual classes are 44%, 24%, 25%, 66%, and 19%, respectively. We note that stars in the sample often exhibited more than one pattern.

At certain times, changes in the U and B bands were markedly different from those in V (e.g. for BU Tau, V744 Her, V923 Aql, and V1294 Aql). We confirm that the LTE-positive variability is more common than the inverse (20 vs 6); in addition, two stars exhibited both types ({zeta} Tau and V1294 Aql). According to our observations, the LTC variability and the LTE-positive variability are almost mutually exclusive.

Among 26 binary systems with previously known orbital solutions, circular orbits are more common than eccentric ones (18 vs 8). As for the brightness variations between different quiescent phases, an increasing trend is less common than a decreasing one (4 vs 7); spanning from -6.5 to +6.0mmag/yr. Our observations provide well-calibrated UBV light curves spanning several decades, offering a valuable dataset for investigations of Be-star variability and tests of various models, including the viscous decretion disc model.

Continuous monitoring is important for the most interesting objects, namely, {beta} Lyr, EW Lac, {delta} Sco, {gamma} Cas, and V1294 Aql.