Debris disc candidates in systems with transiting planets

Monthly Notices of the Royal Astronomical Society (Impact Factor: 5.52). 01/2011; 000:1-5. DOI: 10.1111/j.1745-3933.2011.01133.x
Source: arXiv

ABSTRACT Debris discs are known to exist around many planet-host stars, but no debris dust has been found so far in systems with transiting planets. Using publicly available cat-alogues, we searched for infrared excesses in such systems. In the recently published Wide-Field Infrared Survey Explorer (WISE) catalogue, we found 52 stars with tran-siting planets. Two systems with one transiting "hot Jupiter" each, TrES-2 and XO-5, exhibit small excesses both at 12 µm and 22 µm at a 3σ level. Provided that one or both of these detections are real, the frequency of warm excesses in systems with tran-siting planets of 2-4% is comparable to that around solar-type stars probed at similar wavelengths with Spitzer's MIPS and IRS instruments. Modelling suggests that the observed excesses would stem from dust rings with radii of several AU. The inferred amount of dust is close to the maximum expected theoretically from a collisional cas-cade in asteroid belt analogues. If confirmed, the presence of debris discs in systems with transiting planets may put important constraints onto formation and migration scenarios of hot Jupiters.

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