Editor's Summary

19 August 2010

Orion nebula making waves

The molecular cloud in the Orion nebula, at about 414 parsecs from Earth, gives us our closest view of massive-star formation. It has been predicted from star-formation models that the gases heated and ionized in the process will generate wave-like structures as they are blown over pre-existing molecular gas. These waves have now been observed, in a new series of radio maps of the Orion nebula. The waves are thought to result from Kelvin–Helmholtz instability, a phenomenon seen at the interface between fluids with different densities and velocities, and further observations of such periodic structures should provide insight into the mechanisms of massive-star formation and its effects on the surrounding region of the molecular cloud.

News and ViewsAstrophysics: Waves on Orion's shores

Waves have been discovered in the molecular cloud surrounding the Orion nebula, generated by shearing flows in the cloud. This finding provides clues to the way filamentary substructures form in the interstellar medium.

John Bally


LetterWaves on the surface of the Orion molecular cloud

Olivier Berné, Núria Marcelino & José Cernicharo