More than 30 extra-solar Jupiter-like planets have shorter periods than the planet Mercury .
It is generally accepted that they formed further out , past the ’ snow line ’ ( \sim 1 AU ) , and migrated inwards .
In order to be driven by tidal torques from the gaseous disc , the disc exterior to the planet had to contain about a planetary mass .
The fact that the planets stopped migrating means that their outer disc was removed .
We suggest , following the simulation by Bate et al .
( 2003 ) , that the outer disc was accreted by the planet .
This not only halts migration but removes the outer disc for planets interior to about 2 AU .
The disc further out could have been removed by photoevaporation ( Matsuyama et al .
2003 ) .
Furthermore , as also shown by Bate et al .
( op cit ) this process also provides an upper limit to planetary masses in agreement with the analysis of observed planetary masses by Zucker & Mazeh ( 2002 ) .
In this scenario , the endgame is a race .
The central star is accreting the inner disc and the planet , while the planet is accreting the outer disc .
The planet survives if it accretes its outer disc before being accreted by the star .
The winner is determined solely by the ratio of the mass of the outer disc to the local surface density of the disc .
Some planets are certainly eaten by the central star .