Starspot Simulation Animation | Shih-Yun Tang

EXSPLOSYN Model

Fri, 19 Jun 2026 00:00:00 +0100

This page hosts the full-resolution companion animation for my PhD thesis, Characterization of Young Active Stars for Identifying the Youngest Exoplanets.

The animation below corresponds to Chapter 4.5, Figure 4.14.

Click the animation to open the raw GIF in a new tab.

Description

This animation shows a standard output from the EXSPLOSYN spot simulation code. The panel features a 3D projection of the star displaying the surface spot configurations alongside the corresponding synthetic spotted spectra in the upper-right panel. The bottom-right panels trace the resulting variations in radial velocity (RV) and the equivalent width ratio (EWR) of OH and Fe line.

Specifically, this model presents the Zeeman-Doppler Imaging (ZDI) informed surface reconstruction for the weak-line T Tauri star LkCa4.

LkCa4 EXSPLOSYN H band Spectral Variations

Fri, 19 Jun 2026 00:00:00 +0100

This page hosts the full-resolution companion animations for my PhD thesis, Characterization of Young Active Stars for Identifying the Youngest Exoplanets.

H-band Spectral Comparison

The animation below corresponds to Chapter 4.5, Figure 4.26 of my thesis.

Click the animation to open the raw GIF in a new tab.

Description

This animation tracks variations in the stellar spectrum as a function of rotational phase. The SPIRou observations are shown in black, while the best-fit forward modeling sequence from EXSPLOSYN is plotted in red. For comparison, the dashed blue line represents a standard two-component composite spectrum constructed using fixed atmospheric parameters ($T_{\rm phot} = 3914$ K, $T_{\rm spot} = 2769$ K, and a cool spot filling factor $f_{\rm cool} = 55%$) derived by Gully-Santiago et al. (2017).

LkCa4 EXSPLOSYN Magnetized H band Spectral Variations

Fri, 19 Jun 2026 00:00:00 +0100

This page hosts the full-resolution companion animations for my PhD thesis, Characterization of Young Active Stars for Identifying the Youngest Exoplanets.

H-band Spectral Comparison with Magnetic Field Effects

The animation below corresponds to Chapter 4.6, Figure 4.28 of my thesis.

Click the animation to open the raw GIF in a new tab.

Description

This sequence is similar to the previous animation, but highlights the impact of incorporating magnetic fields (the Zeeman effect) into the model. Here, the SPIRou observations remain in black. The unmagnetized EXSPLOSYN forward model is plotted in red, while the updated EXSPLOSYN model incorporating a $2\text{ kG}$ magnetic field is shown in cyan.

LkCa4 EXSPLOSYN K band Spectral Variations

Fri, 19 Jun 2026 00:00:00 +0100

This page hosts the full-resolution companion animations for my PhD thesis, Characterization of Young Active Stars for Identifying the Youngest Exoplanets.

K-band Spectral Comparison with Magnetic Field Effects

The animation below corresponds to Chapter 4.6, Figure 4.2X of my thesis.

Click the animation to open the raw GIF in a new tab.

Description

This animation demonstrates magnetic effects across two distinct K-band wavelength regions: panel (a) focuses on the highly magnetically sensitive Ti lines, while panel (b) showcases the magnetically insensitive CO molecular bands. In both panels, SPIRou observations are shown in black, the $2\text{ kG}$ EXSPLOSYN model is in red, and a $2\text{ kG}$ two-component composite spectrum built using synmast is represented in cyan.