Exploring the effects of limb darkening on multi-wavelength photometric and spectroscopic studies of extrasolar planets

• Applicant: Professor Dr. Jürgen H.M.M. Schmitt
• Subject Area: Astrophysics and Astronomy
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 402218555

• Final Report Year: 2022

Final Report Abstract

The work carried out in this project resulted in the development of a code that allows a detailed treatment of limb-darkening (independent of ad hoc choices of limb darkening coefficients, geometrical shapes of the bodies involved (i.e., non-spherical shapes of host stars and planets) as well as arbitrary surface structures (i.e., spots, faculae etc.) in the computation of transit light curves. It has also been shown that the animation software Blender can actually be used for “hard” scientific computations and not just “nice images”. While the currently achieved accuracy is on the order of 10^−7 , a denser sampling would – presumably – lead to even more accurate results; this has not been demonstrated explicitly since data with that accuracy are currently not available, however, future data are expected to have much larger accuracies than currently available data on multi-transit systems. At any rate, the tools developed do allow an extremely detailed modeling of transit light curves including the effects of PPOs. We have further shown that PPOs yield insight into the exoplanetary system architecture and it will eventually have to be demonstrated that PPO features, which by necessity are small, can actually be attributed to planet-planet occultations rather than inhomogeneities on the stellar surface. To show the applicability of the software a detailed modeling and parameter study of the multi-transiting Kepler-20 system has been carried out, unfortunately no statistically significant PPO could be detected, only some of the considered configurations appear unlikely.

Publications

• “A new approach to distant solar system object detection in large survey data sets”, A&A, 615, A159
  Perdelwitz, V., Völschow, M., Müller, H. M.
  
• “Modeling light curves of the multi-transiting system Kepler-20 using Blender”, Division for Extreme Solar Systems Abstracts, 2019, 51,310.02
  Müller et al.
  
• "Orbital obliquity sampling in the Kepler-20 system using the 3D animation software Blender", A&A, 2022, 657, A37
  Müller, H. M., Ioannidis, P. and Schmitt, J.H.M.M.