We present Herschel ^ { 1 } spatially resolved images of the debris disc orbiting the subgiant \kappa CrB .
Not only are these the first resolved images of a debris disc orbiting a subgiant , but \kappa CrB is a rare example of an intermediate mass star where a detailed study of the structure of the planetary system can be made , including both planets and planetesimal belt ( s ) .
The only way to discover planets around such stars using the radial velocity technique is to observe ‘ retired ’ A stars , which are cooler and slower rotators compared to their main-sequence counterparts .
A planetary companion has already been detected orbiting the subgiant \kappa CrB , with revised parameters of m \sin i = 2.1 M _ { J } and a _ { pl } = 2.8 AU ( ) .
We present additional Keck I HIRES radial velocity measurements that provide evidence for a second planetary companion , alongside Keck II AO imaging that places an upper limit on the mass of this companion .
Modelling of our Herschel images shows that the dust is broadly distributed , but can not distinguish between a single wide belt ( from 20 to 220AU ) or two narrow dust belts ( at around 40 and 165AU ) .
Given the existence of a second planetary companion beyond \sim 3AU it is possible that the absence of dust within \sim 20 AU is caused by dynamical depletion , although the observations are not inconsistent with depletion of these regions by collisional erosion , which occurs at higher rates closer to the star .