Stellar-MADE project
Hugo Derbey
Summary of my career
I did all my studies at Université Grenoble Alpes. During the first two years of my physics bachelor’s degree, I followed the selective Physique Recherche track, which puts research at the heart of the curriculum: experimental and theoretical research projects, seminars given by researchers, and internships from the second year onwards. This is how I spent four weeks at the European Synchrotron Radiation Facility (ESRF) in 2023, designing experimental setups on the ID31 X-ray diffraction beamline under the supervision of Dr. Jakub Drnec. The following year, I joined the Science Operations Group at the Institut de Radioastronomie Millimétrique (IRAM), where I worked with Dr. Kirsty Butler on data analysis to confirm a never-before-observed gravitational lens configuration.
I then moved on to a master’s degree in physics, specialising in astrophysics in the second year, alongside the Magistère de physique and the ExTReM thematic programme of the Graduate School @UGA. Two experiences drew me towards star and planet formation. The first was a numerical summer school organised within ExTReM, where I ran my first simulations of planet migration in protoplanetary disks with Dr. Nicolás Cuello. The second was my M1 project and internship at IPAG with Dr. Romane Le Gal and Dr. Maxime Tanious, where I studied the molecular cloud surrounding a young protostar to better understand interstellar heritage.
This naturally led me to build my M2 project with Dr. Nicolás Cuello and Dr. Antoine Alaguero. During this year-long project and five-month internship, I used the 3D SPH code Phantom to simulate circumbinary disks in hierarchical triple stellar systems. The goal was to investigate whether a misaligned outer companion could hold a circumbinary disk at an intermediate inclination, as suggested by observations of the V892 Tau system.
Alongside my research, I currently teach geometrical optics to first-year undergraduate students at Université Grenoble Alpes.
Ongoing research
During my PhD, supervised by Dr. Nicolás Cuello (IPAG) and Dr. Jean-François Gonzalez (CRAL, Lyon), I continue working on circumbinary disks in multiple stellar systems. Most stars form in multiple systems, and many close binaries are surrounded by circumbinary disks. In these environments, the central binary carves cavities and spiral arms, while outer companions can tilt and warp the disk. Planet formation there is therefore quite different from the single-star case (and one star is already complicated enough!).
Using Phantom, I will study how these disks evolve under the gravitational influence of all the stars, focusing on alignment mechanisms, angular momentum transport and dust evolution. A first step is to explore the stability of disks in misaligned triple systems, and in particular the axis around which they precess. The simulations will then be post-processed with the radiative transfer code MCFOST to produce synthetic observations that can be compared directly with real data.
The PhD also has an observational side: I will analyse high angular resolution observations of circumbinary disks, notably with ALMA, to constrain the dust distribution, identify substructures (rings, cavities, asymmetries) and estimate grain sizes. Confronting simulations and observations will help us understand which planetary architectures to expect in multiple stellar systems.
Recent highlight
Coming soon!