By Ron Cowen
How do you transform an old coot into a virile young whippersnapper? For a puffy middle-aged star, the cosmic version of taking Viagra seems to be ingesting a nearby companion—then burping up the stellar meal. That appears to be the best explanation for how two aging stars, long past their birthing years, have once again become ripe for making planets, an endeavor normally reserved for the youngest stars in the universe.
At first glance, the two stars in the new study appear young, notes Carl Melis of the University of California, Los Angeles. Both emit a lot of infrared light, a sign that they are surrounded by large, dusty disks that absorb starlight and reradiate it in the infrared. These disks provide the raw material for planet making. Common around newborn stars, the disks usually vanish after several million years.