IFS Seminar with Ada Canet

Assessing the long-term habitability of sub-Neptunes and super-Earths remains a central challenge in exoplanetary
science, as these targets are the most abundant planetary populations, and primary candidates for harboring life. During
their early evolutionary stages, the stability and retention of their primordial hydrogen-rich atmospheres are strictly
governed by stellar activity and high-energy radiation.1 In this context, K-type stars are increasingly recognized as
optimal "Goldilocks" targets, offering a balance of moderate magnetic activity compared to highly active M-dwarfs
and observationally accessible habitable zones.2 Beyond high-energy radiation, this environment is dominated by the
continuous impact of stellar winds. The interaction of these highly supersonic astrophysical plasmas with planetary
envelopes drives severe atmospheric erosion and dictates the overall topology of the system. When a planetary
magnetic field is present, this plasma interaction leads to the formation of a magnetosphere and generates auroral radio
emissions driven by the Electron Cyclotron Maser Instability (ECMI).3
Crucially, the formation, stand-off distance, and morphology of the magnetosphere, as well as the intensity of the
resulting radio emissions, are strongly dependent on the physical properties of the stellar wind, specifically its dynamic
pressure and interplanetary magnetic field (IMF), alongside the strength and topology of the planetary magnetic field.4
Understanding these complex, non-linear star-planet interactions and interpreting emerging observational detections
require rigorous plasma modeling. To address this, we perform 3D numerical simulations using the highly versatile
PLUTO code, solving the equations of ideal magnetohydrodynamics (MHD) to accurately capture the fluid-dynamic
and magnetic coupling between the stellar wind and the planetary environment.
In this talk, we first present our model detailing the interaction between stellar winds and unmagnetized Earth-like
planets during their early evolutionary stages. Our MHD results demonstrate that stellar rotation dictates atmospheric
survival: fast-rotating stars drive the formation of complex fluid-dynamic structures, such as double bow shocks and
induced magnetospheres, that completely strip primordial envelopes, whereas slow rotators allow the atmospheres to
remain largely intact.5
Second, we present an expansion of this computational framework that incorporates planetary magnetic pressure. By
simulating the interaction of K-type stellar winds with magnetized super-Earths and sub-Neptunes, we evaluate
varying magnetic field strengths to predict the formation of magnetospheric boundaries and provide quantitative
estimates of their expected ECMI-driven radio emissions. These advanced MHD models can be applied to specific
observational targets of interest, such as HD73583b, HD73583c, and HAT-P-11b, demonstrating how fundamental
theoretical plasma physics serves as a crucial diagnostic tool for characterizing current and future exoplanetary
detections.
References
[1] Lillo-Box J., et al., A&A 667, A102 (2022)
[2] Lammer H. et al., 2014, MNRAS, 439, 3225
[3] Zarka P., Planetary and Space Science 55 (2007) 598–617
[4] Varela J., et al., A&A 659, A10 (2022)
[5] Canet A., et al., MNRAS 531, 2626–2641 (2024)

BIO
Ada Canet received her B.S. degrees in Physics and Mathematics from the Complutense University of Madrid (UCM),
followed by an M.Sc. in Astrophysics from UCM and the Université de Liège, graduating with honors. She earned
her Ph.D. in Astrophysics with Cum Laude and International Mention from UCM, receiving institutional recognition
for the presentation of her doctoral research on stellar wind interactions with Earth-like exoplanets. She is currently
an Assistant Professor in the Department of Earth Physics and Astrophysics at UCM. In 2026, she was awarded a
Postdoctoral Fulbright Fellowship at the University of Texas at Austin, where she is currently conducting research.
During her international research stays at the Università degli Studi di Torino and Universidad Carlos III de Madrid,
her work was dedicated to developing and implementing new modules for PLUTO, a high-performance numerical
simulation code for astrophysical plasmas developed at the University of Turin.
Her research focuses on computational numerical simulations of astrophysical plasmas, specializing in
magnetohydrodynamic (MHD) modeling of both magnetized and unmagnetized Earth-like planets. This work
investigates MHD structures and the evolution of exospheres and atmospheres, with a particular emphasis on young
planets orbiting highly active stars. As a key member of UCM's AEGORA research group—a world leader in
ultraviolet astrophysics—she complements these computational simulations with observational studies of young
stellar objects, interacting binaries, and the interstellar medium. Through her work within AEGORA, she actively
participates in major space astrophysics missions in the ultraviolet regime, including the Lunar Ultraviolet
Observatory (OUL), the World Space Observatory - UltraViolet (WSO-UV), and the Habitable Worlds Observatory
(HWO). Ada serves as an active referee for The Astrophysical Journal and has published her scientific results in
leading peer-reviewed journals, including Monthly Notices of the Royal Astronomical Society (MNRAS), Astronomy
& Astrophysics (A&A), and The Astrophysical Journal (ApJ).