The changing brightness and spectrum of a Nova
Upper panel: The brightness of Nova Cyg 92 as a function of time, as seen in two different bands of
the International Ultraviolet Explorer (IUE) satellite. The brightness initially drops during the first couple of days
as the initial ejected fireball thins out, then increases again as a thicker shell of gas expands around the White
Dwarf and heats up.
Lower panel: The spectrum of the Nova light in the Ultraviolet (UV) changes with time as the
brightness is changing. Absorption lines in the spectrum first become stronger, then weaker again as the
object first cools, then heats up.
Please hit RELOAD to play movie again.
Back