I think it's amazing that there could be a system with enough comets to block out such a big portion of starlight. It gets my imagination going because when I picture the future of human expansion, I don't see us living on the natural surfaces of planets, putting up with all the ways in which they are ill-suited to our comfort (wrong gravity, wrong color starlight, wrong day/night cycle for our circadian rhythm, wrong atmosphere, wrong temperature range, too much radiation, etc.). I know that people want to address some of these problems with some sort of transforming, and that will make sense on some planets, but most stars will not have eligible ones.
However, most stars will have enough ordinary junk in their orbit that we will be able to manufacture (with self-replicating AI machines) a perfectly awesome and huge spinning habitat that could have a habitable surface area comparable to that of the Earth. The easiest source for the materials for such a habitat are smallish rocks, because it takes so little energy to eject habitat material from a quarry on a rock with such a small gravity well. A colony would simply dispatch an AI-controlled factory that would convert asteroid material into duplicate AI factories, plus fuel and thrusters that get these to other asteroids. Then the factories retool to convert the asteroids into parts for a giant spinning space station, in which the interior light, atmosphere, gravity and temperature are optimized for terrestrial life, while the star-facing exterior is covered with solar panels, and the shady side is a spiky forest of heatsinks. If the orbit is close enough to the star, the panels alone should generate enough energy to power all the systems and more.
It's very 1960's thinking to picture ourselves living on the surfaces of other planets, and yet, even many scientists have not gotten past that obsolete picture. AI technology plus robotics will allow us to thrive even in extrasolar systems that have nothing but perfectly ordinary crap floating in orbit, because perfectly ordinary crap is exactly what we and every important feature of our biosphere are made of.
What's exciting about a system like this is that if there are lots of comets, it means that there's a lot of great crap within arm's reach from which to build a gigantic new home.