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arXiv · 2011.05388

Amplitude Modulation of Short-Timescale Hot Spot Variability

Lauren I. Biddle·Joe Llama·Andrew Collier Cameron·Lisa A. Prato·Moira M. Jardine·Christopher M. Johns-Krull
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Abstract

Variability of Classical T Tauri Systems (CTTS) occurs over a vast range of timescales. CTTS in particular are subject to variability caused by accretion shocks which can occur stochastically, periodically, or quasi-periodically on timescales over a few days. The detectability of young planets within these systems is likely hampered by activity; therefore, it is essential that we understand the origin of young star variability over a range of timescales to help disentangle stellar activity from signatures of planetary origin. We present analysis of the stochastic small-amplitude photometric variability in the K2 lightcurve of CI Tau occurring on timescales of $\lesssim$1 d. We find the amplitude of this variability exhibits the same periodic signatures as detected in the large-amplitude variability, indicating that the physical mechanism modulating these brightness features is the same. The periods detected are also in agreement with the rotation period of the star ($\sim$6.6 d), and orbital period of the planet ($\sim$9.0 d) known to drive pulsed accretion onto the star.

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Lauren I. Biddle, Joe Llama, Andrew Collier Cameron, Lisa A. Prato, Moira M. Jardine, Christopher M. Johns-Krull. 2020-11-10. Amplitude Modulation of Short-Timescale Hot Spot Variability. https://doi.org/10.3847/1538-4357%2Fabc889

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