Chris (preliminary):
The host is a LINER with z=0.541.
It could also be a starburst galaxy. Without [OII], I cannot tell.. If it is a starburst galaxy, then it should not be variable. If it is a LINER, then it is a AGN, and I would guess that some variablity should be expected. For more, see D. Osterbrock, ApJ, 404, 551. A quote from this paper reads" ... the objects called LINERs form a very mixed bag".
Tiles (cross telescope subtraction)