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Doctoral thesis
Open access
English

Know thy star, know thy planet – disentangling planet discovery & stellar activity

ContributorsGiles, Helen
Defense date2019-06-26
Abstract

Kepler and K2 have enabled studies of exoplanets and stars. This thesis focuses on two goals: characterising starspots on Kepler stars and finding and following up K2 exoplanets. Starspot evolution produces quasi-sinusoidal light curves. Fitting ACFs with periodic functions, I found a correlation between starspot size, decay lifetime and stellar effective temperature. This method is used as part of RV follow-up for planet-hosting stars. K2 light curves were analysed using a new pipeline. This generated two confirmed planets: K2-140b, a Jupiter-like planet orbiting in 6.57 days (the 9th hot Jupiter from K2) and K2-311b, a single-transit-event lasting 54 hours. With RV follow-up and tools, this Jupiter-sized planet orbits in ~10 years. This is currently the longest-period transiting planet discovered. This thesis contributes to future exoplanet endeavours to discover smaller planets in distant orbits, by providing techniques for exoplanet follow-up and improving our knowledge and understanding of stellar activity.

eng
Keywords
  • Astrophysics
  • Astronomy
  • Exoplanets
  • Planets
  • Extrasolar Planets
  • Transits
  • Stars
  • Starspots
  • Starspot Decay
  • Kepler
  • K2
  • Photometry
  • Light Curves
Funding
  • Swiss National Science Foundation - NCCR PlanetS
Citation (ISO format)
GILES, Helen. Know thy star, know thy planet – disentangling planet discovery & stellar activity. 2019. doi: 10.13097/archive-ouverte/unige:123850
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Technical informations

Creation09/13/2019 2:56:00 PM
First validation09/13/2019 2:56:00 PM
Update time03/15/2023 6:06:34 PM
Status update03/15/2023 6:06:34 PM
Last indexation01/29/2024 9:58:45 PM
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