Balmer series Reference Libraries
H II Region -- An H II region is an emission nebula associated with hot, young, blue stars, and star forming regions. H II, or singly-ionized hydrogen, is nebular gas ionized by ultraviolet light emitted by these hot, young stars of spectral type O and B. The sizes of H II regions are determined both by the amount of gas present, and by the luminosity of the O and B stars -- the more...
- One of the side scenes of the stage in a theater, or the space included between the side scenes.
- The outside stock exchange, or “curb market,” of Paris.
- A flute or groove on the blade of a sword.
- A section of stage scenery placed in a wing of a theatre.