Orion Nebula - Fabry-Perot high resolution O I /8446 A/ mapping

The Fabry-Perot near-infrared spectrophotometer of the 182-cm Asiago telescope was used for absolute flux measurements of the neutral oxygen line at 8446 A in 22 positions across the surface of the Orion Nebula (M42). From the derived O I/H-beta ratios, starlight excitation appears to be the most efficient mechanism for explaining the unexpected strength of this line.