太阳与恒星天体物理

RR Lyrae stars (RRLs) are old pulsating variables widely used as metallicity tracers due to the correlation between their metal abundances and light curve morphology. With ESA Gaia DR3 providing light curves for about 270,000 RRLs, there is…

Using high-precision photometric data from TESS, medium resolution spectroscopic data from LAMOST, and long-term eclipse timings, we provide orbital parameters for two early-type detached eclipsing binary systems: TYC 3740-2072-1 and TYC…

Analyses of stellar spectra, stellar populations, and transit light curves rely on grids of synthetic spectra and center-to-limb variations (limb darkening) from model stellar atmospheres. Extensive model grids from PHOENIX, a generalized…

In this work, we analyze the ongoing brightening of the poorly studied symbiotic star V4141 Sgr and examine its long-term variability. We present new low-resolution spectroscopic observations of the system in its bright state and combine…

Context. Extreme-ultraviolet (EUV) observations have revealed small-scale transient brightenings that may share common physical mechanisms with larger-scale solar flares. A notable feature of solar and stellar flares is the presence of…

In this work we present the results of our analysis of medium-resolution LAMOST spectra of late-type candidate members of the Pleiades. We have used the code ROTFIT to determine the atmospheric parameters (Teff, logg, and [Fe/H]), radial…

We present a comprehensive analysis of Cyg X-1, utilizing archival high-resolution UV and optical spectra in conjunction with sophisticated atmospheric models. Notably, this is the first investigation to simultaneously analyze UV and…

The interplay between radiative diffusion, rotation, convection, and magnetism in metallic-line chemically peculiar stars is still not fully understood. Recently, evidence has emerged that these effects can work together. Our goal is to…

Here, we present several examples of unusual evolutionary patterns in solar coronal loops that resemble cross-field drift motions. These loops were simultaneously observed from two vantage points by two different spacecraft: the…

Early B-type stars ($M_i=8-15$ M$_\odot$) are frequently in multiple systems, as evidenced by spectroscopic campaigns in the Milky Way (MW) and the Large Magellanic Cloud (LMC). Previous studies have shown no strong metallicity dependence…

HD93129A is an O+O stellar system whose CWR has been mapped by high angular resolution observations at cm wavelengths. The synchrotron nature of the radio emission confirms its particle accelerator status. According to astrometric…

The blue supergiant (BSG) domain contains a large variety of stars whose past and future evolutionary paths are still highly uncertain. Since binary interaction plays a crucial role in the fate of massive stars, investigating the…

Given the uncertain evolutionary status of blue supergiant stars, their multiplicity properties hold vital clues to better understand their origin and evolution. As part of The Binarity at LOw Metallicity (BLOeM) campaign in the Small…

Rapidly rotating classical OBe stars have been proposed as the products of binary interactions, and the fraction of Be stars with compact companions implies that at least some are. However, to constrain the interaction physics spinning up…

Accurate measurements of cosmic ray proton flux are essential for studying the modulation processes of cosmic rays during the solar activity cycle. A proton flux measurement method, based on ground-based neutron monitor (NM) data and deep…

Stars stripped of their hydrogen-rich envelopes through binary interaction are thought to be responsible for both hydrogen-poor supernovae and the hard ionizing radiation observed in low-$Z$ galaxies. A population of these stars was…

Recent detections of gravitational waves from mergers of binary black holes (BBHs) with pre-merger source-frame individual masses in the so-called upper mass-gap, expected due to (pulsational) pair instability supernova ((P)PISN), have…

Stellar activity is fundamental to stellar evolution and the formation and habitability of exoplanets. The interaction between convective motions and rotation in cool stars results in a dynamo process that drives magnetic surface activity.…

The detailed investigation of the polar magnetic field and its time evolution is one of the major achievements of Hinode. Precise measurements of the polar magnetic field are essential for understanding the solar cycle, as they provide…

Coronal dimmings associated with coronal mass ejections (CME) from the Sun have gained much attention since the late 1990s when they were first observed in high-cadence imagery of the SOHO/EIT and Yohkoh/SXT instruments. They appear as…