Amplitude Modulation of Short-Timescale Hot Spot Variability

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.

Accepted for publication in ApJ

References in corpus (14)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system
• Kepler constraints on planets near hot Jupiters
• Dust settling in local simulations of turbulent protoplanetary disks
• Four newborn planets transiting the young solar analog V1298 Tau
• Temperaments of young stars: Rapid mass-accretion rate changes in T Tauri and Herbig Ae stars
• Precise time-series photometry for the Kepler-2.0 mission
• No Clear, Direct Evidence for Multiple Protoplanets Orbiting LkCa 15: LkCa 15 bcd are Likely Inner Disk Signals
• A hot Jupiter around the very active weak-line T Tauri star TAP 26
• Formation of Hot Jupiters through Secular Chaos and Dynamical Tides
• The hot Jupiter of the magnetically-active weak-line T Tauri star V830 Tau
• The magnetic field and accretion regime of CI Tau
• Star Spot Induced Radial Velocity Variability in LkCa 19
• CO Detected in CI Tau b: Hot Start Implied by Planet Mass and M${}_K$

Cited by in corpus (2)

• The Many-Faceted Light Curves of Young Disk-bearing Stars in Taurus as Seen by K2
• Pulsational instability of pre-main sequence models from accreting protostars. I. Constraining the input physics for accretion with spectroscopic parameters and stellar pulsations