Possible Bright Starspots on TRAPPIST-1.

@article{Morris2018PossibleBS,
  title={Possible Bright Starspots on TRAPPIST-1.},
  author={Brett M. Morris and Eric Agol and James. R. A. Davenport and Suzanne L. Hawley},
  journal={arXiv: Solar and Stellar Astrophysics},
  year={2018}
}
The M8V star TRAPPIST-1 hosts seven roughly Earth-sized planets and is a promising target for exoplanet characterization. Kepler/K2 Campaign 12 observations of TRAPPIST-1 in the optical show an apparent rotational modulation with a 3.3 day period, though that rotational signal is not readily detected in the Spitzer light curve at 4.5 $\mu$m. If the rotational modulation is due to starspots, persistent dark spots can be excluded from the lack of photometric variability in the Spitzer light curve… 
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