2018/08/08 by Brett M. Morris, Eric Agol, Leslie Hebb +9
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Exoplanet #Light curve #Photometry (optics) #Photosphere #Physics #Planet #Spectral line #Stars #Starspot #Stellar, planetary, and galactic studies #Transit (satellite) #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.3847/2041-8213/aad8aa
Accepted for publication in ApJL
arxiv created 2018/08/08 · openalex publication_date 2018/08/17 · arxiv updated 2018/08/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract We apply the transit light curve self-contamination technique of Morris et al. to search for the effect of stellar activity on the transits of the ultracool dwarf TRAPPIST-1 with 2018 Spitzer photometry. The self-contamination method fits the transit light curves of planets orbiting spotted stars, allowing the host star to be a source of contaminating positive or negative flux that influences the transit depths but not the ingress/egress durations. We find that none of the planets show statistically significant evidence for self-contamination by bright or dark regions of the stellar photosphere. However, we show that small-scale magnetic activity, analogous in size to the smallest sunspots, could still be lurking undetected in the transit photometry.