太阳与恒星天体物理

Classifying variable stars is crucial for advancing our understanding of stellar evolution and dynamics. As large-scale surveys generate increasing volumes of light curve data, the demand for automated and reliable classification techniques…

This study provides the first comprehensive analysis of eight total-eclipse W Ursae Majoris-type contact binary systems. Ground-based photometric multiband observations were conducted at a Mexican observatory, and new times of minima were…

Light curve analysis of W UMa-type contact binary systems using MCMC or MC methods can be time-consuming, primarily because the repeated generation of synthetic light curves tends to be relatively slow during the fitting process. Although…

Meridional circulation in stratified stellar/planetary interiors in the presence of stable molecular weight gradients remains poorly understood, thereby affecting angular momentum transport in evolutionary models. We extend the downward…

One of the most commonly observed solar radio sources in the metric and decametric wavelengths is the solar noise storm. These are generally associated with active regions and are believed to be powered by the plasma emission mechanism.…

Eclipsing binaries with pulsating components are a distinct subclass of binaries, merging orbital and pulsational analyses. In recent years, that subclass led to the definition of a newly formed branch of tidal asteroseismology. While…

Stellar spectral classification according to the Morgan-Keenan (MK) system remains fundamental to astrophysical studies, yet modern surveys require automated, scalable tools. We present NutMaat, an open-source Python-based package inspired…

Flux emergence is ubiquitous in the Sun's lower atmosphere, where the emerging magnetic flux can reconnect with the pre-existing magnetic field. We investigate plasmoid formation and the resulting multi-thermal emissions during…

One important property in studying the exoplanet population is the host star metallicity ([M/H]). In this study, we derived stellar metallicities and oxygen abundances for 48 M dwarf stars using the near-infrared high-resolution spectra…

Symbiotic stars are binaries in which a cool and evolved star of luminosity class I-III accretes onto a smaller companion. However, direct accretion signatures like disc flickering and boundary layer X-rays are typically outshone or…

The LOw Frequency ARray (LOFAR) is capable of imaging spectroscopy of the Sun in the 10-240 MHz frequency range, with high spectral, temporal, and spatial resolution. However, the complex and rapidly varying nature of solar radio emission -…

Radio emission from massive binary systems is generally of composite nature, showing both a thermal emission component from the winds and a non-thermal component from relativistic electrons accelerated in the colliding-wind region.…

We investigate the relationship between Forbush decreases (FDs) and associated geomagnetic storms, and their links to interplanetary solar wind parameters, using high-resolution minute data. FDs are classified by main-phase decrease steps…

Since the variety of their light curve morphologies, the vast majority of the known heartbeat stars (HBSs) have been discovered by manual inspection. Machine learning, which has already been successfully applied to the classification of…

Plasma turbulence is a ubiquitous dynamical process that transfers energy across many spatial and temporal scales in astrophysical and space plasma systems. Although the theory of anisotropic magnetohydrodynamic (MHD) turbulence has…

We present a study of neutron-capture element abundances (Sr, Y, Zr, Ba, La, Ce, Nd, Pr, and Eu) in a large and homogeneous sample of 160 F-, G-, and K-type planet-host stars located in the northern hemisphere, including 32 stars in…

The V883 Ori system is a rapidly accreting young stellar object that has been used as a laboratory for studying the molecular inventory of young circumstellar disks with high luminosity. We simultaneously fit high resolution spectroscopy…

Low-mass stars and brown dwarfs -- spectral types (SpTs) M0 and later -- play a significant role in studying stellar and substellar processes and demographics, reaching down to planetary-mass objects. Currently, the classification of these…

Over decades of solar wind observations, heavy ions have been observed to have a higher temperature and flow faster than protons in the solar corona and heliosphere. Remote observations have largely been limited to the low corona ($<…

We present a new independent determination for the age of one of the oldest open clusters, NGC 188: $6.41 \pm 0.33$ Gyr. We utilize a novel approach where we jointly fit the radial velocities (RVs) and spectral energy distributions (SED) of…