Retired star found with planets and debris disc

9 April 2013 - ESA's Herschel space observatory has provided the first images of a dust belt - produced by colliding comets or asteroids - orbiting a subgiant star known to host a planetary system. After billions of years steadily burning hydrogen in their cores, stars like our Sun exhaust this central fuel reserve and start burning it in shells around the core. They swell to become subgiant stars, before later becoming red giants. At least during the subgiant phase, planets, asteroids and comet belts around these 'retired' stars are expected to survive, but observations are needed to measure their properties. One approach is to search for discs of dust around the stars, generated by collisions between populations of asteroids or comets. Thanks to the sensitive far-infrared detection capabilities of the Herschel space observatory, astronomers have been able to resolve bright emission around Kappa Coronae Borealis (? CrB, or Kappa Cor Bor), indicating the presence of a dusty debris disc. The star is a little heavier than our own Sun at 1.5 solar masses, is around 2.5 billion years old and lies at a distance of roughly 100 light years.