Stellar streams are sensitive to perturbations from, for example, giant molecular clouds, bars and spiral arms, infalling dwarf galaxies, or globular clusters which can imprint gaps, clumps, spurs, and asymmetries in tails. In addition to these effects, the impact of a major galactic merger on a population of stellar streams remains to be explored

We investigate galaxy populations in the HS 1700+64 protocluster at $z=2.30$, characterized by two prominent linear filaments traced by spatially extended ${\rm Ly} \, \alpha$ blobs. We conducted a wide area mapping of emission line galaxies across the protocluster using the unique combination of three matched narrow-band filters, corresponding to

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

A crucial chemical link between stars and their orbiting exoplanets is thought to exist. If universal, this connection could affect the formation and evolution of all planets. Therefore, this potential vital link needs testing by characterizing exoplanets around chemically-diverse stars. We present the discovery of two planets orbiting the metal

We present the results of deep near-infrared imaging of the recently discovered helium star pulsar binary J1928+1815 situated in the Galactic plane. Our observations did not achieve significant detections, providing limiting magnitudes of J = 23.7 and H = 22.2, which are both 2.4 mag deeper than the expected J and H magnitudes for a modeled

The physically motivated definition of galaxy size proposed recently, linked to the farther location of the in situ star formation, considerably reduces the scatter of the galaxy mass─size relation and provides a viable method to infer the galaxy stellar mass from its size. We provide a similar relation correlating the size of galaxies with the