AST 2002 Lecture 33: 11/30
Document Summary
If a white dwarf is in a close binary: Matter from its companion can be accreted onto the wd (can steal matter from its partner) Eventually it will collect enough hydrogen to start fusion. The matter forms a disk around the wd. Friction in the accretion disk heats it. It emits visible, uv, and even x-ray light. If matter falls onto the wd, h fusion begins. Nothing is really going to happen if its by itself like the sun. The wd temporarily gets brighter nova. They typically increase in brightness considerably for a few days, then fade as it works through the hydrogen. Accretion disk- a rotating disk of gas orbiting a star; formed by matter falling onto the star. The hydrogen build-up on the surface of the white dwarf can ignite into an explosive fusion reaction that blows off a shell of gas.
