DX Andromedae
It has a typical apparent visual magnitude of 15 . 5 during the "quiescent" phase , but becomes brighter ( up to a magnitude of 11 . 0 ) during outbursts recurring with a mean cycle length of 330 days , thus is classified as a dwarf nova of the SS Cygni type . 
<triplet> SS Cygni <subj> dwarf nova <obj> type of variable star