Schematic view of the young stellar populations in NGC 2024. Orange points are Class II stars; circles indicate millimeter detections. The eastern population (left) is young and located near the dense molecular ridge hosting the FIR 1–5 Class 0 sources, which partly shields it from the intense radiation field driven by the ionizing source(s), such as IRS 2b. The western population is older, and more exposed to the ionizing radiation of the primary ionizing source(s) and the cooler IRS 1.