Overview of the photometric data available for each object in our sample. Each color-shaded region corresponds to a different instrument or data set. Red indicates HIPPARCOS, blue indicates INTEGRAL-OMC, green indicates OGLE, black indicates ASAS, brown indicates ANDICAM, yellow indicates data from Lorenzo et al. (2014), and data from TESS are indicated in purple. We note that these ranges indicate the date ranges of the respective data sets, some of which are sporadic and without a regular cadence.