Recombination H110 alpha line in the Orion Nebula
(1992)

Distribution of recombination line H110 alpha emission on a wave length 6.2cm in the Orion Nebula was obtained with the radiotelescope RATAN-600 with the resolution 40" x 6' x 9.7 km/s ( figure 1 ). Slow rotation of the nebula core which looks like thick semienvelope with slow spreading was found. Thin envelope with diameter 0.36 pc and expamding velocitys about +40 and -70 km/sec was also found. The increase of temperature of gas is revealed in this thin layer. Within the framework of model of a stellar wind kinematic parameters of a basic Nebula and thin envelope result in the following picture: approximately 30000 years back weaker exciting stars ( B1-B2 ) were arised and basic exciting star Theta 1C of Orion has appeared approximately 2000 years back.

Figure 1. Profiles of H110 alpha line in a central part of Orion Nebula. The primes marked components relating a thin envelope, extending with large velosity.