太阳与恒星天体物理
We present a preliminary analysis of the largest Forbush Decrease (FD) observed in solar cycle 25 using SEVAN network data. Triggered by consecutive Earth-directed CMEs on May 30 and 31, 2025, this event produced two distinct FD minima and…
Based on optical and infrared survey data spanning $\approx 20$ years of observations, the long-term variability of the polar V379 Vir with a brown dwarf secondary has been studied. By modeling the spectral energy distribution, we constrain…
We performed numerical simulations of magnetic reconnection with different strength of magnetic fields from the solar photosphere to the upper chromosphere. The main emphasis is to identify dominant mechanisms for heating plasmas in the…
In the standard model of solar eruptive events, coronal mass ejections (CMEs) and flares are associated with each other through magnetic reconnection initiated by erupting flux ropes. Observations also reveal an increasing association ratio…
We aim to determine the physical properties of OB stars from the multi-epoch VLT/FLAMES BLOeM spectroscopic survey of the Small Magellanic Cloud. We apply a pipeline designed to analyse large spectroscopic samples of OB stars to the…
We present the first asteroseismic analysis of the bright, nearby red giant star, HD145250. We calculate the global seismic quantities of the star from single-sector, 2-minute TESS photometry, and determine its mass and radius to be ~1.4…
We investigate the impact of geometric corrections to the Bondi-Hoyle-Lyttleton (BHL) accretion scheme applied to evolving symbiotic systems. We model systems where 0.7 and 1 M$_\odot$ white dwarfs accrete material from Solar-like stars…
The Tayler instability (TI) of toroidal magnetic fields is a candidate mechanism for driving turbulence, angular momentum (AM) transport, and dynamo action in stellar radiative zones. Recently \cite{Skoutnev_2024} revisited the linear…
Photometric methods for identifying dark companion binaries - binary systems hosting quiescent black holes and neutron stars - operate by detecting ellipsoidal variations caused by tidal interactions. The limitation of this approach is that…
This study delves into [W60] B90, one of the most luminous and extreme Red Supergiants (RSGs) in the Large Magellanic Cloud (LMC), aiming to search for evidence of episodic mass loss. Our discovery of a bar-like nebular structure at 1 pc,…
The evolution of magnetic braking and dynamo processes in subgiant stars is essential for understanding how these stars lose angular momentum. We investigate the magnetic braking and dynamo evolution of $\beta$ Hydri, a G-type subgiant, to…
Interferometric observations of protoplanetary disks by VLTI and ALMA have greatly improved our understanding of the detailed structure of these planetary birthplaces. These observations have revealed a variety of large-scale disk…
It is shown that a simple quasi-equilibrium analysis of a multi-component plasma can be harnessed to explain catastrophic energy transformations in astrophysical objects. We limit ourselves to the particular class of binary systems for…
The horizontal branch (HB) phase of stellar evolution plays a critical role in understanding the life cycle of stars, particularly in the context of low-mass stars. However, generating theoretical evolutionary tracks for HB stars is…
We perform a systematic study of the preconditioning of the interplanetary (IP) medium due to isolated interplanetary coronal mass ejections (ICMEs). Preconditioning is highly relevant when ICMEs, ejected in close succession and direction,…
Cepheus A HW2 is a well-studied massive young stellar object (MYSO) featuring Class II methanol masers. Recently, certain maser components have been found to flare every five years. This period went undetected in (NEO)WISE photometry due to…
Based on the eclipsing binary catalog provided by \cite{2022ApJS..258...16P}, 84 totally eclipsing contact binaries with stable light curves were selected. The TESS light curves of these 84 targets were studied using the Physics Of…
We report on large-scale radio observations of the Chamaeleon star-forming region obtained with the Australia Telescope Compact Array (ATCA) that led to the definite detection of five young stars and the tentative detection of five more. As…
We generalize a magnetogram-matching Biot-Savart law (BSL) from planar to spherical geometry. For a given coronal current density $\bf{J}$, this law determines the magnetic field $\tilde{\bf B}$ whose radial component vanishes at the…
We compare the radii derived from the asteroseismic scaling relations with those from surface brightness-colour relations (SBCRs) combined with the Gaia DR3 parallaxes for main-sequence (MS) stars. The atmospheric and asteroseismic…