  Massive stars inject mechanical and radiative energy into the surrounding
environment, which stirs it up, heats the gas, produces cloud and intercloud
phases in the interstellar medium, and disrupts molecular clouds (the birth
sites of new stars). Stellar winds, supernova explosions and ionization by
ultraviolet photons control the lifetimes of molecular clouds. Theoretical
studies predict that momentum injection by radiation should dominate that by
stellar winds, but this has been difficult to assess observationally.
Velocity-resolved large-scale images in the fine-structure line of ionized
carbon ([C II]) provide an observational diagnostic for the radiative energy
input and the dynamics of the interstellar medium around massive stars. Here we
report observations of a one-square-degree region (about 7 parsecs in diameter)
of Orion molecular core -- the region nearest to Earth that exhibits
massive-star formation -- at a resolution of 16 arcseconds (0.03 parsecs) in
the [C II] line at 1.9 terahertz (158 micrometres). The results reveal that the
stellar wind originating from the massive star ${\theta}^{1}$ Orionis C has
swept up the surrounding material to create a bubble roughly four parsecs in
diameter with a 2,600-solar-mass shell, which is expanding at 13 kilometres per
second. This finding demonstrates that the mechanical energy from the stellar
wind is converted very efficiently into kinetic energy of the shell and causes
more disruption of the Orion molecular core 1 than do photo-ionization and
evaporation or future supernova explosions.
