Fig11_7 Nova

Fig11_7 Nova

Fig. 11.7 . A classical nova is a thermonuclear explosion that occurs on the surface of a white dwarf star that is in a close orbit with a main-sequence star. The strong gravitational attraction of the white dwarf pulls its nearby companion into an elongated shape, whose outer edge is designated the Roche lobe. Some of the hydrogen in the outer atmosphere of the main-sequence star spills over at the inner Lagrangian point, denoted L1, where the gravitational pull of the two stars is equal. This hydrogen spirals into a rotating accretion disk and down to the white dwarf, igniting an explosion, like a colossal hydrogen bomb.

Copyright 2010, Professor Kenneth R. Lang, Tufts University