The Laser Interferometer Space Antenna (LISA) will explore the yet-uncharted millihertz band of the gravitational-wave (GW) spectrum in between the very low frequencies probed by pulsar timing arrays and the kilohertz window accessible to ground-based observatories. LISA's adoption is scheduled for early 2024 and data analysis methods are well underway, given the novelty and complexity of the expected data. The GalaxyFIT project aims at designing methods that simultaneously measure and describe the LISA noise, the gravitational-wave signals from thousands of sources, plus gravitational-wave backgrounds from astrophysical and cosmological sources. Integrated methods starting from non-ideal interferometric data all the way to data quality assessments of partially resolved sources are a necessity for LISA to reach its science objectives. GalaxyFIT will focus on ultracompact binary sources in the Milky Way where thousands of sources will be individually resolved and many more will result in an unresolved background, dominating the instrument noise and hampering the detection of a cosmological gravitational wave background. Specifically, GalaxyFIT will establish improved methods for detection and characterization of sources in the presence of non-ideal instrumental noise, and assess the impacts of different data quality cuts on astrophysical inference (measurement of Galactic structure parameters and features in the distributions of the binaries) and the measurement of a cosmological background. GalaxyFIT gathers experts on the LISA instrument, data analysis and astrophysical interpretation and aims to address many of the important data analysis and scientific goals that France has assumed for the LISA Mission, and pave the way for maximised scientific output with the LISA data. GalaxyFIT will also train a new generation of scientists towards this goal.

Some meteorites contain xenolithic clasts that are made of material genetically unrelated to the host rock. Xenolithic clasts can be composed of materials not sampled by meteorites. They may potentially represent an underexploited source of primitive, volatile-rich material. During the four-year CLASTS project, we will combine petrographic, mineralogical, spectral, isotopic and chronological approaches in order to 1. Identify and determine primary characteristics and parent body history of xenolithic clasts in a series of meteorites from the CC and NC reservoirs, 2. Characterize primordial planetesimals no longer present in the asteroid belt through the study of clasts composed of materials not sampled in the meteorite collection; 3. Constrain the incorporation mechanism (primordial vs. subsequent accretion) and timing of the clasts in their host rock. CLASTS will leverage the complementary range of analytical and scientific expertise present in IPAG, CEREGE, CRPG and OCA.

Binary asteroids are key objects to understanding the intimate internal nature of asteroids as for them, it is possible to compute the total mass and the bulk density. The formation itself of asteroid satellites can be the result of collisions, fission and rotational spin up, whose issue depends on the internal structure. However, the currently known sample of binaries is heavily biased by the currently available techniques, ad a whole range of possible separation / sizes has remained inaccessible up to now. In GaiaMoons we will exploit the ultra-accurate astrometry of forthcoming data releases by the Gaia mission, to discover a large number of Main Belt binaries belonging to this unknown population, and to better characterise the known ones. The new approach consists in measuring the astrometric perturbation induced by the presence of a satellite. With the additional information provided by photometry and Gaia spectroscopy, we will determine their physical properties (mass, density), the orbital parameters of the companion, and the composition. In turn, composition and density will allow us to constraint the asteroid internal porosity, thus discriminating between the compact or fragmented internal structure inherited from the evolution history. We also exploit data obtained so far by stellar occultations, and observe new events to obtain an independent validation of our discoveries. Our project is based on a collaboration between experts of Gaia at the Observatoire de la Côte d'Azur, specialists in occultation techniques at Observatoire de Paris and in photometry at the University of Poznan.