The recently discovered phosphorus-rich stars pose a challenge to stellar evolution and nucleosynthesis (that is, the formation of chemical elements in stellar interiors) theory, as none of the existing models can explain their extremely peculiar chemical abundances pattern. Apart from the large phosphorus (P) enhancement, such stars also show enhancement in other light (O, Mg, Si, Al) and heavy (e.g., Ce) elements. Thanks to the Spanish Service Time at the Nordic Optical Telescope, we have recently obtained high-resolution optical spectra of two optically bright phosphorus-rich stars

For more than six decades, the quest to understand the formation of hot (about 20,000−30,000 K) extreme horizontal branch (EHB) stars in Galactic globular clusters has remained one of the most elusive in stellar evolutionary theory. Here we report on two discoveries that challenge the idea of the stable luminosity of EHB stars. The first mode of EHB variability is periodic and cannot be ascribed to either binary evolution or pulsation. Instead, we attribute it here to the presence of magnetic spots: superficial chemical inhomogeneities whose projected rotation induces the variability. The

The main objective of the NASA OSIRIS-REx mission is the collection of material from the surface of primitive asteroid (101955) Bennu, and to bring it back to the Earth. To provide general context to the results obtained from the analysis of this sample it is fundamental to carry out an extensive study of the surface of the asteroid. To do that, the spacecraft is provided, among other instruments, with an optical camera (MapCam) equipped with 4 color filters b’, v, w, and x, centered at 473, 550, 698, and 847 nm, respectively. This set-up allowed to do color studies, i.e., to analyze how the