TT Ari is a cataclysmic variable of the VY Sculptoris class. The VY Scl stars typically remain in a high state like the nova-like variables, and do not show outbursts like those of dwarf novae. What makes them different from the novalikes is that they occasionally undergo deep fading events, and current evidence suggests the accretion stream from the secondary turns off during these events. Why this happens is not known. TT Ari first showed signs of fading in July and August of 2009, and observers covered the star intensely through the initial fade to 14th magnitude, and again when it reached a deeper quiescent level around V=16.5. As of mid-2011, TT Ari has essentially returned to its normal, high state. The nature of the fading over the past two years isn't yet understood.
Prepared By: Matthew Templeton