It is with great sadness that we convey the news of the passing of Monique Pick on May 3, 2025 at the age of 91.
After studying at the École de Physique et Chimie (Paris), from which she graduated in 1956, Monique Pick joined Jean-Louis Steinberg’s group at the Observatoire de Paris in Meudon that developed solar radio observations at Nançay (Cher). Her thesis focused on the study of Type IV solar radio emissions and their relationship with other solar and geophysical phenomena. These Type IV emissions are associated with magnetized clouds (coronal mass ejections) propagating at high speed between the Sun and the Earth, and they can be associated with energetic particles of solar origin and geomagnetic storms. The key result of her thesis concerns the link between Type IV radio emission and the presence of high-energy particles in space. This research led Monique to develop “multi-messenger” studies using, from the end of the 1950s, the diagnostics of energetic particles obtained from ground-based instruments (detection of energetic protons by neutron monitors and by observations of polar ionospheric absorptions) and then, in the 1960s, the first satellite data of energetic protons. It was also at this time that she obtained the then intriguing result that particle-associated flares in space were mostly located West of the Sun’s central meridian – a result that is easily understood with Parker’s later theory of the solar wind.
From the beginning of her career, Monique Pick developed original methods for studying the Sun and the interplanetary medium by combining her radio observations with all available data: optical observations and diagnostics of particles on the ground, then with the development of space, all kinds of data from the measurement of particles and waves from the kilometer range to gamma rays. She was a pioneer in this approach, which is now widely followed. Through her thesis and following work, Monique also contributed to the development of the physics of solar–terrestrial relationships, which gave rise years later to space weather, a discipline that is widely developed today.
After a fire destroyed the first solar radio interferometer operating in metric wavelengths, at Nançay in 1971, Monique Pick led the construction of a new 2-dimensional radioheliograph. This instrument, built in several stages by a group of researchers and technicians at Meudon and Nançay, has recently been renovated. It remains the only radio telescope in the world dedicated to imaging the corona and solar activity in decimetric/metric radio waves. and it is still widely used today as a complement to the most recent space probes studying the Sun and the heliosphere (ESA/NASA Solar Orbiter and NASA’s Parker Solar Probe).
After a stay at the University of Chicago in 1966, then meetings with physicists from the University of Minnesota who were developing the first solar X-ray instruments, Monique Pick very quickly developed collaborations with American space physicists, in particular at the Space Sciences Laboratory of the University of California–Berkeley, then the Goddard Space Flight Center for the Solar Maximum Mission launched in 1980. From that moment on, the development of the Nançay Radioheliograph has continued to the present day in connection with solar and heliospheric missions in addition to X-ray instruments, particle detection instruments, and coronagraphs (ESA/NASA Ulysses probe in 1990, ESA/NASA SOHO spacecraft in 1995, NASA STEREO probes in 2006, Parker Solar Probe in 2018 and ESA/NASA Solar Orbiter spacecraft in 2020). Collaborations between ground-based and space-based instruments were actually quite rare in the 1980s and Monique Pick had a pioneering and driving role in this field that is now widespread in astrophysics.
After having led the Radioheliograph Group until 1984, Monique Pick then took over the management of the Nançay Radio Astronomy Station where she held two four-year terms and where her role was a driving force in defending, in particular, the renovation of the large Nançay radio telescope (FORT project). During her mandates, Monique Pick firmly established the Nançay station, with state–region support, and established strong links with the University of Orléans and its Laboratoire de Physique et de Chimie de l’Environnement et de l’Espace (LPC2E). This proactive approach made it possible to obtain positions and funding for the instruments, thus ensuring the sustainability of the research programmes.
After this mandate as director of Nançay and a few years as Astronomy Project Manager at the Ministry of Research, Monique Pick returned to her activities as a researcher in solar physics, and she continued to work with passion as an emerita researcher (her last article dates from 2020) on solar radio emissions, energetic particles, and associated coronal mass ejections. She was the driving force behind a site for the visualization and sharing of solar data in the radio, ground, and space domains (commonly known as Radio Monitoring). At the beginning of her retirement as an emerita, she also made a major contribution to the first European studies in space weather.
After having been one of the founding members of CESRA (the Community of Solar Radio Astronomers) in 1970, Monique Pick contributed to the development of solar radio astronomy in Europe but also later in India and China. She helped build several important instruments and train several generations of radio astronomers.
Monique will be remembered as a brilliant researcher who carried out her work with passion. A woman of exceptional energy, she welcomed many foreign researchers who visited the Observatoire de Paris–Meudon, and always showed great concern and support for early career researchers.
Monique is survived by her beloved three children and six grand-children. Messages can be sent to her family at [email protected]
Nicole Vilmer, Alain Kerdraon, Claude Mercier, Ludwig Klein, her former colleagues from the Paris Observatory