NATS 1870 Lecture Notes - Lecture 21: Kinetic Energy, White Dwarf, Photon

• School: York University
• Department: Natural Science
• Course: NATS 1870
• Professor: Robin Kingsburgh

Document Summary

Part of interstellar medium material between the stars. Supernova remnants remains of exploded stars: dark dense, cool (few degrees above absolute zero) Lots of dust: reflection blue nebulae caused by scattering of dust. Red common in nebulae is a specific emission line of hydrogen. 656 nm red ->transition when electron drops 3rd to 2nd energy level. How this happens: ( h-atoms ) : protons orbited by electron. Hot star -> gives off many uv photons. H-atom becomes ionized" the absorption of uv photon causes the electron to totally detach from the atom. Gas surrounding the hot stars has lots of free electrons in it. For red recombination emission: electron becomes re-attached to proton at a very high energy level. > each time it drops, a photon is emitted e- Green: common emission line is at 501 nm -> from o2+ - oxygen atom with 2 electrons removed.