Domain, Specialties : Astrophysique
Research Unit : DAp / LDE3
Summary
The discovery of an exoplanet orbiting a Sun-like star (Mayor & Queloz 1995), recognised by the 2019 Nobel Prize in Physics, opened a new era in planetary science. Since then, exoplanet detection, atmospheric characterisation, and star–planet interactions have become major research areas (Winn & Fabrycky 2015; Madhusudhan 2019; Cuntz et al. 2000). Star–planet magnetic interactions (SPMI) offer a probe of stellar winds and planetary magnetic fields, with implications for atmospheric evolution and habitability (Shkolnik et al. 2015; Vidotto et al. 2013; Strugarek et al. 2022). The search for SPMI has spanned decades, and although convincing detections remain rare, observational evidence continues to accumulate (Shkolnik et al. 2003, 2008; Cauley et al. 2019; Ilin et al. 2025; Revilla et al. 2026). Our team has worked on modelling and detecting SPMI for more than a decade and has developed AstroSPI (Yang & Strugarek, in preparation), an efficient simulation tool for exploring SPMI without running computationally demanding MHD simulations. This project aims to expand the SPMI sample by using AstroSPI to identify promising observational targets whose planets orbit within the stellar Alfvén surface, where magnetic perturbations can propagate back to the host star. If time allows, fully 3D MHD modelling of those new systems will be carried out as well during the internship. The internship has the potential to substantially expand the pool of SPMI candidates and guide future observations, laying a foundation for more comprehensive studies of these interactions.
Full description
The aim of this project is to expand the sample of promising targets for the study of star–planet magnetic interactions (SPMIs). SPMI provides a potential probe of stellar winds and planetary magnetic fields, with important implications for planetary atmospheric evolution and habitability (Shkolnik et al. 2015; Vidotto et al. 2013; Strugarek et al. 2022). Searches for SPMI have been conducted for several decades, and although convincing detections remain rare, observational evidence continues to accumulate (Shkolnik et al. 2003, 2008; Cauley et al. 2019; Ilin et al. 2025; Revilla et al. 2026).
Fewer than ten planetary systems have reported candidate SPMI detections, compared with more than 6,000 known exoplanets. Optical searches generally require time-intensive, multi-epoch observations with high-resolution spectroscopy, making blind surveys impractical because of the substantial telescope time involved. At the same time, the limited number of observational detections makes it difficult to identify the most promising targets for follow-up observations, thereby perpetuating a vicious cycle.
This project will establish a sample of potential SPMI targets using AstroSPI, an SPMI modeling tool developed from more than a decade of experience in the field. The AstroSPI package is designed to provide an accessible alternative to computationally intensive magnetohydrodynamic simulations while incorporating the principal physical processes relevant to SPMI. It allows users to focus on understanding how different physical assumptions, models, and system parameters affect the predicted interaction, without becoming overwhelmed by the computational complexity of detailed simulations. The package is therefore particularly suitable for young researchers, enabling them to become rapidly involved in SPMI research while developing experience in exoplanetary data, stellar winds, magnetic interactions, and scientific modeling.
The intern will first compile the relevant stellar and planetary parameters for known exoplanetary systems using AstroSPI functions that retrieve data through application programming interfaces from major exoplanet archives. The intern will then become familiar with the physical processes underlying SPMI, select appropriate physical models and input parameters, and identify systems in which the planet is likely to enter the sub-Alfvénic region and maintain magnetic connectivity with its host star. AstroSPI will subsequently be used to estimate the resulting interaction power and temporal variability, and assess whether the predicted signals could be detected through multi-epoch spectroscopic observations. Finally, the intern will synthesize the results and prepare a scientific paper presenting the candidate sample to the astronomical community.
The internship will therefore comprise the following stages:
Literature review and physical framework (~1 month): Develop a broad understanding of SPMI and identify the physical and observational parameters that determine whether an SPMI signal is likely to be detectable. Become familiar with the AstroSPI code and its workflow.
Sample construction and statistical analysis (~ 2 months): Construct a sample of planetary systems with potentially detectable SPMI signals and perform a statistical analysis of their properties. Investigate the relationships among the relevant stellar, planetary, and interaction parameters; determine why particular systems are promising observational targets; and interpret the physical properties predicted by AstroSPI. If time allows, the most promising targets will be modeled using the in-house 3D MHD star-planet interaction simulation code (based on the PLUTO code) to perform the most realistic assessment of the system possible to date.
Scientific writing (~1 month): Prepare the internship report and an initial draft of a scientific manuscript presenting the methods and results.
The results will contribute to a more systematic understanding of star–planet magnetic interactions and will provide a prioritized target list for future observational campaigns. Closely connected to the rapidly developing field of exoplanet research, the internship will also provide a strong scientific foundation for students interested in pursuing a PhD. The project is linked to the ERC ExoMagnets project led by A. Strugarek at CEA, DAp-AIM, which today consists of a team of 2 PhD students and 3 postdoctoral researchers (including F. Yang).. The intern will work alongside a team of researchers with expertise in stellar and exoplanetary physics, including A. S. Brun, S. Mathis, R. García, and A. García-Muñoz.
Location
Saclay
Internship conditions
- Internship duration: 4 months
- Level of study: Bac+4/5
- Training: Master 1
- Continuation in PhD thesis: No
- Application deadline: 4 mars 2027
Experimental skills
Language : English