Context. Currently, one of the standard procedures used to determine stellar and wind parameters of massive stars involves to comparing the observed spectral lines with a grid of synthetic lines. These synthetic lines are calculated using non-local thermodynamic equilibrium radiative transfer codes. In this standard procedure, after estimating the

Variability studies have proven to be a powerful diagnostic tool for understanding the physics and properties of active galactic nuclei (AGNs). They provide insights into the spatial and temporal distribution of the emitting regions, the structure and dynamics of the accretion disc, and the properties of the central black hole. Here, we have

Massive stars are progenitors of supernovae, neutron stars and black holes. During the hydrogen-core burning phase, their convective cores are the prime drivers of their evolution, but inferences of core masses are subject to unconstrained boundary mixing processes. Moreover, uncalibrated transport mechanisms can lead to strong envelope mixing and

Close-in giant exoplanets with temperatures greater than 2,000 K (`ultra-hot Jupiters') have been the subject of extensive efforts to determine their atmospheric properties using thermal emission measurements from the Hubble Space Telescope (HST) and Spitzer Space Telescope 1-3. However, previous studies have yielded inconsistent results because

Aims: Our goal is to calculate the circular velocity curve of the Milky Way, along with corresponding uncertainties that quantify various sources of systematic uncertainty in a self-consistent manner. Methods: The observed rotational velocities are described as circular velocities minus the asymmetric drift. The latter is described by the radial

White dwarf stars are the most common stellar fossils. When in binaries, they make up the dominant form of compact object binary within the Galaxy and can offer insight into different aspects of binary formation and evolution. One of the most remarkable white dwarf binary systems identified to date is AR Scorpii (AR Sco). AR Sco is composed of an M