Detection of deuterium Balmer lines in the Orion Nebula
  The detection and first identification of the deuterium Balmer emission lines, D-alpha and D-beta, in the core of the Orion Nebula is reported. Observations were conducted at the 3.6m Canada-France-Hawaii Telescope, using the Echelle spectrograph Gecko. These lines are very narrow and have identical 11 km/s velocity shifts with respect to H-alpha and H-beta. They are probably excited by UV continuum fluorescence from the Lyman (DI) lines and arise from the interface between the HII region and the molecular cloud. 
G. Hebrard (1), D. Pequignot (2), A. Vidal-Madjar (1), J. R. Walsh (3)   and R. Ferlet (1) ((1) IAP, (2) DAEC, (3) ESO)