2007ApJ...661.1192V

We study the survival of gas planets around stars with masses in the range 1-5 M_☉, as these stars evolve off the main sequence. We show that planets with masses smaller than one Jupiter mass do not survive the planetary nebula phase if located initially at orbital distances smaller than 3-5 AU. Planets more massive than two Jupiter masses around low-mass (1 M_☉ on the main sequence) stars survive the planetary nebula stage down to orbital distances of ∼3 AU. As the star evolves through the planetary nebula phase, an evaporation outflow will be established at the planet's surface. Evaporating planets may be detected using spectroscopic observations. Planets around white dwarfs with masses M_WD≳0.7 M_☉ are generally expected to be found at orbital radii r≳15 AU. If gas planets are found at smaller orbital radii around massive white dwarfs, they had to form as the result of the merger of two white dwarfs.