The coordinates of the variable, comparison, and check stars are listed in Table 1. The B−V values of these stars are from the Hipparcos Catalogue, while those magnitudes in the H, J, and K bands are from the 2MASS All-Sky Catalog of Point Sources (Cutri et al. 2003). However, as shown in Table 1, there is a big color difference (more than 0.6 mag) between the variable and comparison stars.