WISE has discovered about 100 brown dwarf stars so far, the closest is 9 light years away

There hasn't been a great deal of news lately on WISE (the infrared telescope that surveyed the whole sky a year back), but that doesn't mean that work isn't ongoing: so much data has been sent back that it's taking a long time to sift through it, and follow-up work to confirm brown dwarfs takes quite some time, but so far about 100 brown dwarf stars have been discovered. There are two things in particular about discovering brown dwarfs through WISE, and they are:

1 - the possibility of brown dwarfs extremely close to us. I mention this quite a bit, and though we're still waiting the possibility remains high that there are brown dwarfs closer even than Alpha Centauri.

2 - because WISE is a full sky survey, we will eventually be able to use the data to approximately determine just how frequent brown dwarfs are, and thus know that much more about a part of the universe we haven't really known much about at all.

As for just how close nine light years is: that would make it the eighth closest to us. Not bad, though we would probably need to see something under about 6 light years for its discovery to be a really big deal.