Sky map with the complete sample of stars. Purple, blue, cyan, golden, and red symbols represent the O-, B-, A-, F-, and K- and M-type stars, respectively. This color code is the same in all the plots unless otherwise specified. The central green cross denotes the center of the Per OB1 association taken from Mel’nik & Dambis (2017). The large green circle indicates a 4.5-degree circle around the center. The small green circles show the positions of h and χ Persei. The background image, used for reference, was taken from DSS-red.