The search for planets around pulsating white dwarf stars

We are implementing a proven technique to search for extrasolar planets with a different sensitivity from other methods, using the pulsations of white dwarf stars as intrinsic clocks. We will search more than one hundred stars over the next decade for the effects of reflex orbital motion in changing light travel times and accelerations caused by any planets orbiting these stars. To become a white dwarf, a main sequence star must pass through the red giant phase, which might consume its inner planets but is likely to leave more distant ones intact. Our technique is sensitive to parent stars with progenitors of 1-4 solar masses, a range of metallicities, and planets in the range 2-20 AU. This range of parameters is largely unexplored and is likely to remain so until space based missions are launched.