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تسجيل مستخدم جديدThe Formation and Evolution of Planetary Systems (FEPS): Discovery of an Unusual Debris System Associated with HD 12039
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We report the discovery of a debris system associated with the $sim 30$ Myr old G3/5V star HD 12039 using {it Spitzer Space Telescope} observations from 3.6 -- 160$mu$m. An observed infrared excess (L$_{rm IR}$/L$_{ast} = 1times10^{-4}$) above the expected photosphere for $lambda gtrsim 14mu$m is fit by thermally emitting material with a color temperature of T$sim 110$ K, warmer than the majority of debris disks identified to date around Sun-like stars. The object is not detected at 70$mu$m with a 3$sigma$ 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 $gtrsim 7 mu$m that reside in a belt orbiting the star at 4--6 AU. An alternate model dominated by smaller grains, near the blow-out size $asim 0.5mu$m, located at 30-40AU 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 $sim$ few $times 10^{2}$yrs.
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