We examine the possibility of detecting signatures of surviving
Uranus-Neptune-like planets inside planetary nebulae. Planets that are not too
close to the stars, orbital separation larger than about 5 AU, are likely to
survive the entire evolution of the star. As the star turns into a planetary
nebula, it has a fast wind and a strong ionizing radiation. The interaction of
the radiation and wind with a planet may lead to the formation of a compact
condensation or tail inside the planetary nebula, which emits strongly in
Halpha, but not in [OIII]. The position of the condensation (or tail) will
change over a time of about 10 years. Such condensations might be detected with
currently existing telescopes.Comment: Latex, uses aasms4.sty, 10 pages, preprin