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Grimble, William; Kastner, Joel; Sargent, B.; Stassun, Keivan G. (2025).Ìý.ÌýAstrophysical Journal, 995(1), 86.Ìý

To better understand protoplanetary disks—the disks of gas and dust around young stars where planets form—scientists need models that can explain both their spectra (how they emit light at different wavelengths) and their physical structure. In earlier work, the authors developed a combined approach called the EaRTH Disk Model, which links observational data from infrared spectra with radiative transfer models (simulations of how light moves through and interacts with matter).

In this study, they improve one part of that model: how temperature is distributed across the disk. Instead of using a more complex method that requires breaking the disk into many small pieces for calculation, they introduce a simpler mathematical description that still captures how temperature varies with location. This new approach uses an empirical (data-driven) relationship between spatial properties of the disk, making it easier for models to fit real observations while staying physically realistic.

They tested the updated model using infrared data from the Spitzer Space Telescope, focusing on transition disks (disks with gaps or holes that may indicate planet formation). The results provide insights into the disks’ composition (mineralogy) and structure, including evidence for grain growth and processing—key steps in the early stages of planet formation.

Figure 1. Model fit plots of TZTD empirical mineralogical analysis of Spitzer/IRS spectra of targets indicated in Table . Red: cool-disk component constituents; blue: warm-disk component constituents; see Figure Set in the  for legend of dust components.