太阳与恒星天体物理
The interaction of a fast magnetoacoustic wave with a magnetic null point is studied in the context of the sympathetic flare phenomenon. Attention is paid to steepening the wave caused by the finite-amplitude effects in a non-uniform plasma…
This study quantifies how uncertainty in physically meaningful coronal mass ejection (CME) and solar-wind inputs propagates into forecast-relevant diagnostics from eruption to 1 AU. We use a semi-analytic erupting flux rope (EFR) model to…
Continuum emission from a solar flare observed with the Extreme ultraviolet Imaging Spectrometer (EIS) on board the Hinode satellite is used to obtain the radiometric calibration of the instrument. The flare had a GOES class of M8, and…
We present a self-consistent tidal evolution framework that couples binary evolution from MESA to the full linear tidal response from GYRE-tides. Applying this framework to TOI-5882, a subgiant hosting a short-period brown dwarf, we show…
The study of stellar multiplicity offers important constraints on the structure of the Galaxy as well as stellar and planet formation and evolution. Focusing on the most immediate solar neighbourhood benefits from obtaining both complete…
Energetic electrons accelerated at coronal reconnection sites during solar flares precipitate into the lower solar atmosphere, generating nonthermal emissions and regulating energy deposition. However, how their transport and precipitation…
The presence of massive O-type stars with surfaces enriched by CNO-cycle products has been known since the early 1980s. For many years, internal rotational mixing was assumed to be the dominant mechanism responsible for this chemical…
In this paper, we simulate the magnetic flux evolution at different heliocentric distances during two solar-maximum Carrington rotations (CRs) using the time-evolving coronal magnetohydrodynamic (MHD) model COCONUT to investigate the ``open…
Non-thermal power-law distribution functions are ubiquitous in astrophysical, space, and laboratory kinetic plasmas, but their origin remains unclear. A related puzzle is the temperature inversion of the solar corona. We show that these…
We investigate dispersive and kinetic effects on the evolution of a two-dimensional kinked Alfv\'en wave packet by comparing results from MHD, Hall-MHD and hybrid simulations of a low-$\beta$ plasma. We find that the Hall term determines…
Context. Ellerman bombs (EBs) are observational signatures of small-scale magnetic reconnection, key to understanding the lower solar atmosphere. While their role in active regions has been widely studied using the H$\alpha$ line,…
Thermohaline convection is a standard chemical mixing process in stellar interiors, yet its mixing efficiency is not fully settled. Competing theories predict turbulent diffusion coefficients, $D_\mu$, that can differ by orders of…
The frequency of pressure (p) mode in $\delta$~Scuti stars can exceed the Nyquist limit of \textit{Kepler} long-cadence photometry. {These 'super-Nyquist frequencies' (SNFs) are observed as 'reflected' peaks at lower frequencies, i.e., they…
Due to computational efficiency and numerical stability limitations, coronal simulations constrained by static magnetograms are typically performed first and then used to drive inner-heliosphere (IH) models. In this paper, we calculate the…
High-quality, short-cadence photometry from TESS enables the detection of rapid oscillators with unprecedented sensitivity. In this work, we conduct a homogeneous search for high-frequency variability using 20-second cadence light curves…
Metallicity can play a significant role in massive binary evolution through its impact on the opacity within stellar interiors and wind-driven mass loss. In this work, we investigate how the double neutron star (DNS) delay time distribution…
High resolution spectral observations of transition region spectral lines capture the signatures of energy deposition and redistribution at the boundary between the lower and upper atmosphere, and have significant relevance for…
Reconnection-driven nanoflares are widely considered a leading mechanism for coronal-loop heating, but their direct fingerprints in the tenuous coronal plasma remain elusive. The recently discovered coronal nanojets offer a potential probe…
Hot subdwarf binaries with white dwarf companions with orbital periods of less than two hours are progenitor candidates for massive single white dwarfs as well as a variety of thermonuclear explosions. Our aim is to determine the binary…
We report the discovery of six new variable stars identified through an exploratory analysis of several sky fields observed by the author using a small telescope and a CMOS camera. The search employed simultaneous photometry of hundreds of…