Ellipsoidal red giant binaries are a particular class of binary stars where the primary gets tidally deformed by the interaction with the companion. They are the prelude stage before binary interactions, and the study of their population properties is therefore of great relevance to understanding the effects of tidal circularization and the binary

The contact phase represents a crossroad in the evolution of massive binary stars. Depending on the internal physics, the predicted end products can vary greatly including various exotic objects such as Be stars, magnetic massive stars, LBVs and gravitational wave sources. This phase also offers a unique observational laboratory to study binary

The 2.7 µm absorption band, represented by OH groups, in the near-infrared reflectance spectra of primitive Solar System bodies could be an indicator of the cause and degree of space weathering. We compared the absorption bands of particles sampled from the surface (chamber A) and the excavated subsurface (chamber C) on the C-type asteroid Ryugu by

Exoplanets classified as super-Earths are commonly observed on short-period orbits, close to their host stars, but their abundance on wider orbits is poorly constrained. Gravitational microlensing is sensitive to exoplanets on wide orbits. We observed the microlensing event OGLE-2016-BLG-0007, which indicates an exoplanet with a planet-to-star mass

There is now a large sample of stars observed by the Kepler satellite with measured rotation periods and photometric activity index S ph. We use this data, in conjunction with stellar interiors models, to explore the interplay of magnetism, rotation, and convection. Stellar activity proxies other than S ph are correlated with the Rossby number, Ro

The original Kepler mission has delivered unprecedented high-quality photometry. These data have impacted numerous research fields (e.g., asteroseismology and exoplanets), and continue to be an astrophysical goldmine. Because of this, thorough investigations of the ~200 000 stars observed by Kepler remain of paramount importance. In this paper, we