Latest Balmer series Stories
Astronomers have long known that in many surveys of the very distant Universe, a large fraction of the total intrinsic light was not being observed.
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 luminous the stars are, the larger the H II region can be. H II regions are found within the spiral...
- A transitional zone between two communities containing the characteristic species of each.