Combining integral field spectroscopy and coronagraphy: new optical techniques to image habitable zone exoplanets with future space and ground-based instruments (M/F)

Job Description

Thesis Subject

Direct imaging of exoplanets represents one of the most thrilling and rapidly advancing domains in contemporary astronomy. This method enables the study of exoplanetary atmospheres by capturing light directly emitted or reflected by these distant worlds. While current technology already allows the characterization of large gas giants, the ultimate ambition of direct imaging is to extend this capability to Earth-like planets. Such an achievement would enable the measurement of atmospheric compositions and even the search for potential biosignatures, marking a monumental leap in our understanding of planetary systems beyond our own. However, the extreme contrast between the brightness of host stars and the faint light of their orbiting planets poses a formidable instrumental challenge. Detecting an exoplanet in this context is comparable to spotting a firefly next to a lighthouse from thousands of kilometers away.
Coronagraphs are sophisticated optical instruments specifically designed to address this challenge. Their primary function is to suppress the overwhelming starlight, thereby allowing the detection of the much fainter exoplanet signal. The next generation of giant telescopes, including the European Extremely Large Telescope (ELT) in Chile and NASA's Habitable Worlds Observatory, will heavily rely on these advanced coronagraphic techniques. These telescopes aim to image Earth-like planets located within the habitable zones of nearby stars. The Planetary Camera and Spectrograph (PCS), a second-generation coronagraphic instrument planned for the ELT, is specifically designed to explore the habitable zones around red dwarf stars, where rocky planets could potentially exist. Meanwhile, HWO will focus on detecting habitable-zone planets around stars similar to our Sun. Both of these ambitious missions require the development of new coronagraphic techniques to achieve the extreme levels of star light suppression necessary to detect these faint and distant worlds.The ECHOES project, led by Johan Mazoyer and funded by the European Research Council (ERC), aims to significantly advance the field of exoplanet imaging by developing innovative coronagraphic techniques tailored for these missions. This PhD opportunity is fully funded as part of the ECHOES ERC project.
The main objective of this doctoral research is to integrate coronagraphs with actively controllable optics (deformable mirrors), and multiwavelength technology (integral field spectroscopy), to create regions in the image where starlight is actively suppressed to reveals hidden exoplanets that would otherwise be lost in the glare of their host stars. The primary goal of this PhD is to develop a novel active algorithm capable of achieving real-time starlight suppression across all wavelengths.
The PhD candidate will begin by developing the new algorithm in simulation, leveraging advanced computational tools to model and refine its performance. Following this, the candidate will validate the algorithm's effectiveness under controlled laboratory conditions using an optical experimental platform at the Paris Observatory. This step is crucial for ensuring the algorithm's robustness and reliability. Finally, the candidate will have the opportunity to demonstrate the algorithm's capabilities at the Very Large Telescope in Chile, where it will be rapidly applied to the detection and characterization of exoplanets.
Activités
The PhD will employ a combination of simulation, optical engineering, and experimental validation:
• Imaging processing and control algorithms: Use and develop existing coronagraphic simulation tools in python to develop innovative algorithms.
• Optical engineering: Collaborate with an optical engineer to integrate an IFS prototype on the THD2 experimental testbed.
• Experimental physics: Conduct tests on the THD2 testbed to validate the algorithm's performance under realistic conditions.
• On-Sky observations: Participate in observing runs at the VLT in Chile to test the algorithm with the SPHERE+ instrument.
Compétences
ECHOES is an interdisciplinary project which values diverse expertise: we welcome applicants from a wide range of backgrounds, even if you never studied astrophysics previously! Candidates should hold a Master's degree in Physics or Astrophysics, Optics, or computer science, with an interest in instrumentation, experimental work or signal processing. Experience with programming (Python) is essential. The candidate will work in a collaborative, interdisciplinary and international environment: fluency in English, both written and spoken, is required for effective scientific communication.

Your Work Environment

The successful candidate will be part of the exoplanet team at LIRA / Paris Observatory - PSL. Our team, and Dr. Mazoyer in particular, is committed to fostering a diverse and dynamic work environment by actively recruiting individuals of all genders and nationalities. In Paris observatory, arguably the world oldest institution for astronomical research, our team is one of the largest and most dynamic exoplanet research groups in Europe, in particular for direct imaging. LIRA's researchers have been heavily involved in the building of most current and future direct imaging instruments providing a unique access to these instruments: at the Very Large Telescope (VLT / SPHERE) and its associated interferometer (VLTI / GRAVITY), for the James Webb (MIRI coronagraph) but also in future instruments like the Roman Coronagraphic Instrument (NASA's upcoming high-contrast imaging mission) and MICADO (the first light instrument of the Extremely Large Telescope).
The project provides a collaborative network, engaging with leading experts in optics, astrophysics, and machine learning from institutions such as ESO, NASA, and ONERA. This PhD in astronomical instrumentation for future space missions sits at the intersection of engineering, and astrophysics, a uniquely interdisciplinary opportunity in a very promising field. It is a great opportunity for applicants interested in starting a high impact academic career but also open exciting job prospects in space agencies or industries, in optics, aerospace, or advanced high-tech instrumentation.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions