Presentation #150.11 in the session “Star Clusters: Galactic, Extragalactic & Simulated”.
Joner&Hintz (2015) presented a standardized color index based on filters both centered on the Hα spectral line akin to the historically used Hβ color index. This Hα color index can be used to find Hα equivalent width and effective temperature of the object being observed. Previous research done on observing open star clusters using this color index has resulted in a second population of stars adjacent to the main-sequence appearing in color-magnitude diagrams. This work uses newer data taken with the Hα filters along with precise Gaia-astrometry data to investigate this second population of stars and presents standardized, membership-decontaminated color-magnitude diagrams for NGC869, NGC884, and NGC752.