Spinning Worlds is the title given on the archive to the doctoral thesis of Henriette Schwarz, produced during her PhD work at Leiden Observatory. The thesis gathers her studies of exoplanet atmospheres and of the rotation of young planets and brown dwarf companions.
Chapter outline
- Introduction. Sets the scene for measuring atmospheres and spin from the ground.
- Evidence against a strong thermal inversion in HD 209458 b. A look at whether the temperature in this hot Jupiter’s atmosphere rises with altitude, based on high-dispersion spectroscopy. A version of this work also appears in the publications list.
- The slow spin of the young substellar companion GQ Lupi b and its orbital configuration. A measurement of how quickly this companion rotates and how that fits with its orbit.
- Spin measurement of the substellar companion GSC 6214-210 b with CRIRES. The same approach applied to another young companion, using the CRIRES spectrograph.
- Spin measurements of young substellar companions: the case of HIP 78530 b. A further rotation study; the method behind it is illustrated on the cross-correlation page.
A reflective opening
The thesis is described as opening with a personal passage. It speaks of looking up at the stars, picturing each one as the centre of its own system, and wondering what these distant spinning worlds are like, how they formed, and whether anyone is out there. That curiosity frames the technical chapters that follow.
How the pieces connect
The chapters share one idea: light from a faint planet carries information about its air and its motion. By splitting that light into a fine spectrum, researchers can identify molecules, estimate temperatures and measure rotation. Comparing several young objects then shows how spin may depend on mass, age and distance from the host star.