The farthest stars we can see with our naked eye are somewhere around 4,000 light years away.. depending on conditions, location, etc. Considering the 5 - 10 billlion year or so average life span of a typical star, it's unlikely that many of the stars we see have burned out or gone nova since the light left them. Also, analysis of the light we do see enables us to determine where in it's life cycle a star is. A star like Betelgeuse may possibly have gone nova already, since we know it is in the final stages of it's life cycle. But not that many of the visible stars are in that state as far as we can tell.