太阳与恒星天体物理

Between 2017 and 2024, the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory has observed numerous white-light solar flares (WLFs). HMI spectro-polarimetric observations of certain WLFs, in particular the X9.3…

The association of the Vela Pulsar with the Vela Supernova Remnant has long supported the hypothesis that core-collapse supernovae yield neutron stars, but its surrounding stellar population now offers new insights into progenitor…

Determining stellar ages is challenging, as it depends on other stellar parameters in a non-linear way and often relies on stellar evolution models to infer the underlying relation between these parameters and age. This complexity increases…

Avalanche models running in a self-organized critical regime have proven powerful in reproducing the power-law distributions and scale invariance that characterize the statistical properties of solar flares. They are often interpreted as…

In recent years supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity planet searches. We used eight years of Sun-as-a-star radial velocity observations from HARPS-N to measure the…

Using both analytical and numerical means, we demonstrate that linear stability analysis of a hydrodynamic stratified atmosphere or a 1D coronal loop model in non-adiabatic settings features a thermal continuum corresponding to highly…

The analysis of the meridional displacement velocity of individual solar pores and sunspots has been performed. In the period May 2010\,-\,March 2025 of observations in the continuum of the \textit{Solar Dynamics Observatory/Helioseismic…

We present the analysis of four new extremely metal poor turn-off stars thanks to high-resolution spectra obtained with the Subaru/HDS spectrograph. We determined the abundances and upper limits of Li, C, Mg, Ca, Sr, and Ba. Metallicities…

The single-degenerate (SD) model is one of the principal models for the progenitors of Type Ia supernovae (SNe Ia). However, it faces some challenges, the primary being its inability to account for the observed SN Ia birth rate. Many…

We demonstrate that dark matter interactions can profoundly influence stellar nucleosynthesis in the early universe by altering thermodynamic gradients and modifying nuclear reaction rates within primordial stars. Incorporating a dark…

We investigate the infrared variability of carbon stars in the Large Magellanic Cloud (LMC). Our sample consists of 11,134 carbon stars identified in both visual and infrared bands. Among these, 1,184 objects are known Mira variables based…

Based on high-resolution near-infrared photometric data from the James Webb Space Telescope (JWST) targeting the Large Magellanic Cloud (LMC), this study attempts to evaluate the feasibility and sensitivity limits of variable star detection…

Large SEPs can cause adverse space weather hazard to humans technology and such events are especially associated with halo coronal mass ejections (CMEs). But in turn, a significant portion of halo-CMEs are not associated with large SEPs.…

An analysis of the photometric growth and decay rates of sunspots and pores was carried out. According to the \textit{Solar Dynamics Observatory/Helioseismic and Magnetic Imager} (SDO/HMI) data for the period 05.2010-03-2025, $\approx…

Aims. With the aim to reveal the effects of the magnetic field to the multi-band activity of dwarf stars, we search for associated radio emission for an extensive list of 14 915 brown dwarfs and 15 124 flaring stars. Methods. We utilised…

The first few hours of a supernova (SN) contain significant information about the progenitor system. The most modern wide-field surveys that scan the sky repeatedly every few days can discover all kinds of transients in those early epochs.…

Split main-sequences (MSs) and extended main-sequence turn-offs (eMSTOs) have been observed in nearly all Magellanic Clouds clusters younger than 2 Gyr. More recently, Hubble Space Telescope (HST) ultraviolet photometry uncovered a puzzling…

The Fe K$\alpha$ fluorescence line ($\sim 6.4$ keV) has been observed during solar and stellar flares. Two emission mechanisms of the Fe K$\alpha$ line, photoionization and collisional ionization, have been discussed, and the aim of this…

We present the analysis of a microlensing event KMT-2022-BLG-0086 of which the overall light curve is not described by a binary-lens single-source (2L1S) model, which suggests the existence of an extra lens or an extra source. We found that…

Using the Bayesian Analysis of Stellar Evolution-9 (BASE-9) code and Gaia DR3, Pan-STARRS, and 2MASS data, we identify photometric binaries in 35 open clusters (OCs) and constrain their masses. We find a strong correlation between the…