Wra 751, a luminous blue variable developing an S Doradus cycle

Abstract

Aims. The object Wra 751 is a luminous blue variable that lately exhibits strong changes in light and color. We summarise the available photometry of Wra 751, present new photometric observations, and discuss these data with special attention on the systematic differences between the various data sources. In addition, we establish an empirical relationship between and for this class of stars.