Triggers:CNe

• there is roughly 30 novae per year in the Milky Way and about 20 in other galaxies
• absolute magnitude <math>M_V = -8 mag</math>
• amplitude between 6 and 15 mag
• quick rise of few days
• slow decline, between few days and 100 days (fast: type A, slow: type B, very slow: type C)
• 15 days after maximum its Mv = -5.5mag, independent on speed or class

Recurrent novae:

• are produced by a white dwarf star and a red giant circling about each other in a close orbit
• recurrent every 10-100 years
• smaller amplitude: 4-9 mag
• M_V at minimum is about 0-1 mag
• example: RS Oph - 3 outbursts between 1957 and 1991 (AAVSO), exhibits some small variation in the baseline in minimum
• decline within few days