Lets say I am talking about a view like [this supernova - 13 billions light year away](http://www.scientificamerican.com/article.cfm?id=sn1987a-dust). In short can Hubble bring any star into focus in the entire universe? And if so, to what definition? 

I also wonder, how much time would time would it need to focus on a distant star or planet, in comparison to a closer one?