An emission nebula is a nebula formed of ionized gases that emit light of various wavelengths. The most common source of ionization is high-energy [...] emitted from a nearby hot star. Among the several different types of emission nebulae are H II regions, in which star formation is taking place and young, massive stars are the source of the ionizing photons. [1]
- Emission nebula - Wikipedia 22/10/06[↩]
