Detectability of planetary rings around an extrasolar planet from reflected-light photometry

A 6-page 4-figure paper to appear in the proceedings of the IAU Colloquium 200 (IAUC 200) \'Direct Imaging of Exoplanets: Science and Techniques\', October 3-7, 2005, Nice, France, C. Aime and F. Vakili, Eds., Cambridge University Press (CUP)The next generation of high-contrast imaging instruments will provide the first unresolved image of an extrasolar planet. While the emitted infrared light from the planet in thermal equilibrium should show almost no phase effect, the reflected visible light will vary with the orbital phase angle. We study the photometric variation of the reflected light with orbital phase of a ringed extrasolar planet. We show that a ring around an extrasolar planet, both obviously unresolved, can be detected by its specific photometric signature. Keywords: Stars: planetary systems -- Planets: rings -- Extrasolar planet characterizatio