If this man's calculations are correct, asteroid impacts may be the least of our problems. We'd have to colonize other star systems to get the eggs out of the basket for this one.

(Thanks to fellow blogger Bob Ballard for the heads up)

Two points off the top of my head. The first is that devastation on this massive scale has never occurred in our past. The great extinctions of the geological past, to my knowledge, involved serious increases in the rate of extinction, but nothing like the overwhelming cataclysm that Dr. Dar proposes. These events are heightened in our minds eye by 1)time compression (they occur over hundreds of thousands, if not millions of years), and 2)sampling issues (only a fraction of species are preserved in the record). Just as an example, ferns have been around for maybe 600 million years, at least. These should be long extinct, by Dr. Dar's hypothesis.
The other issue is the nature of stars and the vast distances of interstellar space. How likely is it that a star in our neighborhood might behave in this manner? How likely is it that it would happen in our (or our children's, or children's children's, ad infinitum)lifetimes. I expect that when you take into account the time and distance factors, this ceases to be an issue. Seems like fatalism to me.

I wasn't proposing that it was something we should be doing anything about, other than things we'd like to be doing anyway, like developing warp drive. ;-)

Well, if Earth does cross paths with exploding stars, it'll be a bittersweet victory for us rabid environmentalists. Maybe we should start building super massive shelters for cockroaches and fleas to insure their survival when the big moment comes. We should also draft some legislation to insure that no human is allowed to take refuge from the radiation so they are exterminated to make a better world for the cockroaches.

I see this guy has been reading Greg Egan's _Diaspora_.

Shameless plug: I did some semi-original reporting on this; it's at http://avoyagetoarcturus.blogspot.com/2002_05_01_avoyagetoarcturus_archive.html#85074612.