Absolute color-magnitude diagrams. Left: diagrams based on Gaia EDR3. Gray points show all the stars in the K2 image mosaic. The cleaned CMD is shown with the blue points. Variables are indicated with larger symbols. Right: CMD based on the Pan-STARRS DR1 survey. The bottom plots show the areas around the RR Lyrae instability strip. Dark and light blue points are the regular and peculiar RRc stars, respectively; RRab stars are shown in red.