Starspots as an Explanation for the Mysterious IYJ Continuum Excess Emission in Classical T Tauri Stars

An accurate estimation of the continuum excess emission from accretion spots and inner circumstellar disk regions is crucial for a proper derivation of fundamental stellar parameters in accreting systems.

However, the presence of starspots can make disentangling the complicated multi-component emission in these systems challenging.

Subtraction of a single-temperature spectral template is insufficient to account for the composite stellar emission, as we demonstrated in a recent campaign involving Weak-Lined T Tauri Stars.

Here, we model the moderate resolution near-infrared spectra of Classical T Tauri Stars, presenting new spectral models that incorporate spotted stars plus emission from accretion hot-spots and a warm inner disk, allowing us to simultaneously reconstruct the entire 0.8-2.4 micrometer spectrum of our sixteen targets.

Using these models, we re-derive the continuum excess emission.

Our results indicate that accounting for starspots resolves the need to include a previously proposed intermediate temperature component in the IYJ excess, and highlights the importance of a proper treatment of starspots in studies of accreting low-mass stars.

;Comment: Accepted for publication in ApJ