Very small, active day flying moth with long antennae (slightly clubbed at end). Bright variable coppery iridescent sheen to wings visible in bright sunshine. Family Incurvariidae (see Australian Moths IFB Common 1963, p. 24-5).
Glenn. I see references online suggest this species is associated with Acacia baileyana. Perhaps this species is quite common in the ACT? Are there many other species in this family (Adelidae) to be seen in the ACT?
It's hard to say whether something is common, but I've seen it on the wing a few times in Canberra. There is another very similar species, N. sparsella, which is similar to topazias and your photo could be either one. There is also the genus Ceromitia which has a number of named and unnamed species present in Canberra. They are plainish grey species compared to Nemophora, but still have the very long antennae.
Looking at this some more, there are 3 Nemophora species that have been recorded in the ACT, and it isn't possible to be certain which one it is (or even another). I'll change the identification to Nemophora sp.