Research

My main research interest is on the architectures of exoplanet systems. The first step is to detect and confirm these systems, which in my case involves using the transit method illustrated in the figure below. Shown in the bottom left plot is an image from the TESS mission, which is a space telescope that looks for exoplanets by measuring the variation in brightness of stars. The hatched, red area in the image is a mask around a star for which we are measuring the brightness as a function of time. When or if a planet passes in front of its host star (bottom right), it blocks a small fraction of the light. By taking several images we can create a light curve as shown in the top plot below, where each dot represents a measurement of the brightness of the star. Note the variation as shown in the image is exaggerated for illustrative purposes. Here it's on the order of 50%, however, the typical variation for a planet-to-star radius ratio as shown in the bottom right plot is on the order of a few percent as shown in the light curve. From this light curve, we can—among other things—determine the size of the planet and its orbital period and thus its orbital separation.

I have been involved in the discovery and characterization of a number of exoplanet systems discovered by TESS, like a trio of gas giants on short period orbits (TOI-1820, TOI-2025, and TOI-2158) or the discovery of a hot super Neptune right in the Neptunian desert (TOI-1288).

I find it especially interesting to learn about the so-called obliquities of these systems. The obliquity is the angle between the stellar rotation axis and the orbital axis of the planet. This quantity can tell us something about the planets' formation and migration history. We can measure the obliquity through the so-called Rossiter-McLaughlin (RM) effect by, for instance, looking at the distortion of the stellar spectral lines during a planetary transit. This distortion traces the path of the transiting planet as it crosses the rotating stellar disk, as shown in the left plot in the video below. The overall effect is a change in the radial velocity (RV) of the star, which is shown to the right. By gauging the morphology of this curve, we can deduce the projected obliquity of the system. For more details on the RM effect check out our paper on the HD 332231 system.

I also have a strong interest in asteroseismology, the study of stellar oscillations. These oscillations can be used to determine the stellar properties with high precision. For instance, I have been involved in a seismic study on one of the first (suspected) planet-hosting stars, γ Cephei A.

Software

I really enjoy coding and making small publicly available software packages with decent documentation. Listed below are some of my better ones:

Thesis

My thesis "Starchitectures" can be found here.

Publications

I've (co-)authored several peer reviewed papers as

First author

Second author

Third author

A full library of papers, where I've contributed can be found on the NASA ADS.