Triggers:CVs

There is a very large variety of behaviours of CVs.

VY Sculptoris

A subclass of cataclysmic variables exhibiting occasional drops by several magnitudes at irregular intervals. The prototype of the class had shown a deep low-state in 2008, first since 1983 (Greiner et al. 2009).

• amplitude: several magnitudes
• drop time scale: 10-30 days
• low state lasts for about 100 days
• some periodicity (P about 10 days) is present
• mechanism not well understood
• some of VY Scl stars are supersoft X-ray sources during optical low-states.
• V504 Cen has period of 4.21h and went down by 6 mag in 2006 and remained in it for nearly a year.