Planet-bearing stars in Spitzer

Combining this new data with 42 already published observations of planet-bearing stars, we find that 14 of the 146 systems have IR excess at 24 and/or 70um. Only one star, HD 69830, has IR excess exclusively at 24um, indicative of warm dust in the inner system analogous to that produced by collisions in the solar system's asteroid belt.

For the other 13 stars with IR excess the emission is stronger at 70um, consistent with cool dust (<100K) located beyond 10AU, well outside of the orbital location of the known planets.