Context. The physical parameters of the sunspot are not fully understood, especially the height dependence of the magnetic field. So far, it is also an open question as to which heights the He I 10 830 Å spectral line is formed at. Aims: Our aim is to investigate the magnetic and dynamical properties in the atmosphere above a sunspot, from the

We studied the effects of cluster environments on galactic structures by using the TNG50 cosmological simulation and observed galaxies in the Fornax cluster. We focused on galaxies with stellar masses of 10 8 − 12 M ⊙ at z = 0 that reside in Fornax-like clusters with total masses of M 200c = 10 13.4 − 14.3 M ⊙. We characterized the stellar

Aims: Our science goals are to characterise the optical properties of Y dwarfs and to study their consistency with theoretical models. Methods: A sample of five Y dwarfs was observed with three optical and near-infrared instruments at the 10.4m Gran Telescopio Canarias. Deep near-infrared (J- or H-band) and multicolour optical images (z-, i-, r-, G

Galaxy clusters at low redshift are dominated by massive quiescent galaxies hosting stellar populations 10 Gyrs old, indicating that they were formed in the early universe when clusters were still in the process of being assembled (i.e., protoclusters). The rapid growth of galaxies within protoclusters is driven by the efficient transformation of

Context. In the context of charge-coupled devices (CCDs), the ultraviolet (UV) region has mostly remained unexplored after the 1990s. Gaia DR3 offers the community a unique opportunity to explore tens of thousands of asteroids in the near-UV as a proxy of the UV absorption. This absorption has been proposed in previous works as a diagnostic of

New boron abundances or upper limits have been determined for eight early B stars in the young Galactic open cluster NGC 3293, using UV spectra obtained by the Hubble Space Telescope Cosmic Origins Spectrograph. With previous observations, there are now 18 early B stars in this cluster with boron measurements. Six of the newly observed stars have