During his PhD studies, Marcus investigated the intricate architectures of exoplanetary and binary star systems. Using data from the Nordic Optical Telescope and the space telescope Gaia, he examined the alignment between stellar rotation and the orbits of companion stars and planets, offering new insights into their formation and evolution. His findings reveal that most close binary systems are perfectly aligned, whereas wider binaries exhibit a striking correlation between orbital eccentricity and misalignment.

Marcus also contributed to advancing astrometry for exoplanet detection, distinguishing false positives and contributing to the first-ever confirmation of an exoplanet detected by Gaia astrometry. His work underscores the potential of combining astrometry with other techniques to precisely map planetary systems.

The PhD degree was completed at the Department of Physics and Astronomy, Aarhus University.

This summary was prepared by the PhD student.

Time: Monday, May 26th, 2025 at 13.00
Place: Building 1525, room 626, Det Skæve Rum, Department of Physics and Astronomy, Ny Munkegade 120, Aarhus University, 8000 Aarhus C.
Title of dissertation: Mapping Orbital Architectures
Contact information: Marcus Lovmand Marcussen, e-mail: Marcuslmarcussen@gmail.com, tel.: +45 61779499
Members of the assessment committee:
Professor David Hobbs, Department of Physics, Lund University.
Professor Johan Peter Uldall Fynbo, Niels Bohr Institute, University of Copenhagen
Professor Jan Joachim Arlt (chair), Department of Physics and Astronomy,  Aarhus University
Main supervisor: Professor Simon Albrecht, Department of Physics and Astronomy,  Aarhus University
Co-supervisor: Assistant Professor Mia Sloth Lundkvist, Department of Physics and Astronomy,  Aarhus University
Language: The PhD dissertation will be defended in English