The dust, planetesimals, and planets of HD 38529

HD 38529 is a post-main-sequence G8 III/IV star (3.5 Gyr old) with a planetary system consisting of at least two planets having M sin i of 0.8 and 12.2 M-Jup, semimajor axes of 0.13 and 3.74 AU, and eccentricities of 0.25 and 0.35, respectively. Spitzer observations show that HD 38529 has an excess emission above the stellar photosphere, with a signal-to-noise ratio (S/N) at 70 mu m of 4.7, a small excess at 33 mu m (S/N 2: 6), and no excess < 30 mu m. We discuss the distribution of the potential dust-producing planetesimals from the study of the dynamical perturbations of the two known planets, considering in particular the effect of secular resonances. We identify three dynamically stable niches at 0.4-0.8, 20-50, and beyond 60 AU. We model the spectral energy distribution (SED) of HD 38529 to find out which of these niches show signs of harboring dust-producing planetesimals. The secular analysis, together with the SED modeling results, suggest that the planetesimals responsible for most of the dust emission are likely located within 20-50 AU, a configuration that resembles that of the Jovian planets +Kuiper Belt in our solar system. Finally, we place upper limits (8 x 10(-6) lunar masses of 10 mu m particles) to the amount of dust that could be located in the dynamically stable region that exists between the two planets (0.25-0.75 AU).