Context. The physical conditions in stellar atmospheres, such as temperature, velocity, and magnetic fields, can be obtained by interpreting solar spectro-polarimetric observations. Traditional inversion codes, while successful, are computationally demanding, however, especially for lines whose formation is complex and dictated by nonlocal

We report the discovery of a new black-widow millisecond pulsar, PSR J1544–2555, associated with the Fermi-Large Area Telescope (LAT) source 4FGL J1544.2–2554. Optical, radio, and gamma-ray observations confirmed its nature as a compact spider binary system. Optical photometry from ULTRACAM revealed a $\sim$2.7-h orbital period, guiding MeerKAT

The Gaia BP/RP spectra provide an excellent opportunity to search for extremely metal-poor (EMP; [M/H] ≤ –3.0) stars. In this study, we assess the potential of our Gaia BP/RP-based candidate catalog, vetting newly identified EMP candidates with higher-resolution follow-up observations. The candidates are selected based on the metallicity derived

Despite their importance, the dynamical properties of massive stars remain poorly understood. Rotation is a key driver of internal mixing and angular momentum transport, significantly influencing massive star evolution. However, constraining rotation from spectroscopy is challenging, as spectral lines often exhibit excess broadening beyond rotation

Gamma-ray bursts (GRBs) offer a powerful window to probe the progenitor systems responsible for the formation of heavy elements through the rapid neutron capture (r-) process, thanks to their exceptional luminosity, which allows them to be observed across vast cosmic distances. GRB 241105A, observed at a redshift of $z = 2.681$, features a short

Broad-band mid-infrared (MIR) imaging with high-spatial resolution is useful to study extended dust structures in the circumnuclear regions of nearby active galactic nuclei. However, broad-band imaging filters cannot distinguish dust continuum emission from emission lines, and so accounting for the emission line contamination becomes crucial in