2006ApJ...638.1070H

We report the discovery of a debris system associated with the ∼30 Myr old G3/5V star HD 12039 using Spitzer Space Telescope observations from 3.6-160 µm. An observed infrared excess (L_IR/L_*=1x10^–4) above the expected photosphere for λ≳14 µm is fit by thermally emitting material with a color temperature of T∼110 K, warmer than the majority of debris disks identified to date around Sun-like stars. The object is not detected at 70 µm with a 3 σ upper limit 6 times the expected photospheric flux. The spectrum of the infrared excess can be explained by warm, optically thin material comprised of blackbody-like grains of size ≳7 µm that reside in a belt orbiting the star at 4-6 AU. An alternate model dominated by smaller grains, near the blowout size a∼0.5 µm, located at 30-40 AU is also possible but requires the dust to have been produced recently, since such small grains will be expelled from the system by radiation pressure in approximately a few times 10² yr.