Figure 5-19: R I V U X G
Analyzing the Composition of a Distant Nebula The glowing gas cloud in this Hubble Space Telescope image lies 210,000 light-years away in the constellation Tucana (the Toucan). The red light emitted by the nebula has a wavelength of 656 nm, characteristic of an emission line from hydrogen gas. Hot stars within the nebula emit high energy, ultra violet photons, which ionize hydrogen (removing the electron). When the electron returns to the atom, it jumps towards the center and gives off emission lines.
Analyzing the Composition of a Distant Nebula The glowing gas cloud in this Hubble Space Telescope image lies 210,000 light-years away in the constellation Tucana (the Toucan). The red light emitted by the nebula has a wavelength of 656 nm, characteristic of an emission line from hydrogen gas. Hot stars within the nebula emit high energy, ultra violet photons, which ionize hydrogen (removing the electron). When the electron returns to the atom, it jumps towards the center and gives off emission lines.
(NASA, ESA, and A. Nota, STScI/ESA)