Color–color diagram for the sources (dots) for which we recorded the LO events listed in Table 2. The left and right panels are for the nights of September 25 and 26, respectively. Note the different scales. The solid and dashed lines are the loci of the unreddened giant and dwarf stars, respectively, according to Bessell & Brett (1988). The arrow is the extinction vector for A_V = 10 mag, according to Rieke & Lebofsky (1985).