Context. The photospheric Evershed flow is normally oriented radially outward, yet sometimes opposite velocities are observed not only in the chromosphere but also in the photospheric layers of the penumbra. Aims. We studied the velocity field in a special case of an active region with two mature sunspots, the lesser of which formed several days

We present the commissioning results and first scientific observations from the newly installed TWIST (TWenty Inch Survey Telescope) observatory ─ a 50 cm telescope equipped with an sCMOS (scientific complementary metal-oxide-semiconductor) camera providing a $36.1\times 24.1$ arcmin $^2$ field of view ─ housed in the former enclosure of the Super

Context. Massive contact binaries (CBs) are crucial objects for understanding close binary evolution and stellar mergers. Study of these objects has been hampered by a scarcity of observed systems, particularly of B-type systems which are expected to dominate this class. Aims. We bridge this observational gap by mining a large sample of massive CB

Context. WASP-69 b and KELT-11 b are two low-density hot Jupiters, which are expected to show strong atmospheric features in their transmission spectra. Such features offer valuable insights into the chemical composition, thermal structure, and cloud properties of exoplanet atmospheres. High-resolution spectroscopic observations can be used to

Context. The vast majority of the most iron-poor stars in the Galaxy exhibit strong carbon enhancement, with C/H ratios about two orders of magnitude below solar. This unusual chemical composition likely reflects the properties of the gas cloud from which these stars formed, having been enriched by one, or at most a few, supernovae. A remarkable