There is increasing evidence that single-star evolutionary models are unable to reproduce all of the observational properties of massive stars. Binary interaction has emerged as a key factor in the evolution of a significant fraction of massive stars. In this study, we investigate the helium (Y(He)) and nitrogen surface abundances in a comprehensive sample of 180 Galactic O-type stars with projected rotational velocities of ≤150 km/s. We found a subsample (~20% of the total, and ~80% of the stars with Y(He) ≥ 0.12) with a Y(He) and nitrogen abundance combined pattern that is unexplainable by
The rocky planet GJ 1132 b, with Earth-like mass and radius, is a prime candidate for atmospheric studies. Previous observations with Hubble and JWST yielded conflicting results about its atmosphere. This study used three transit observations with the CRIRES+ instrument to search for He i, HCN, CH₄, and H₂O in GJ 1132 b's atmosphere. No clear atmospheric signals were detected, but upper limits for CH₄, HCN, and H₂O were established. The results suggest that if GJ 1132 b has an atmosphere, it is not dominated by hydrogen. The work highlights the challenges of detecting high molecular weight
It’s been decades since the need to study other stars to understand the past, present and future of the Sun was realized. One important aspect that has been investigated is the magnetic activity of stars for which we cannot fully grasp the mechanisms involved. Indeed, the origin of stellar magnetic cycles or the dependence of the magnetic activity on the stellar properties are not completely understood. This knowledge improves not only our understanding of the physics involved in stellar evolution but also affects the study of the Sun to better predict high-energy events and the better