相关论文: Compact Ca II K Brightenings Precede Solar Flares:…

The abundance of chlorine is determined from X-ray spectra obtained with the RESIK instrument on {\em CORONAS-F} during solar flares between 2002 and 2003. Using weak lines of He-like Cl, \ion{Cl}{16}, between 4.44 and 4.50 \AA, and with…

We report on X-ray flares that were observed from the active galactic nucleus I Zwicky 1 (I Zw 1) in 2020 January by the NuSTAR and XMM-Newton observatories. The X-ray spectrum is well-described by a model comprised of the continuum…

We present the first detections by the NASA K2 Mission of oscillations in solar-type stars, using short-cadence data collected during K2 Campaign\,1 (C1). We understand the asteroseismic detection thresholds for C1-like levels of…

Solar oscillations are expected to be excited by turbulent flows in the intergranular lanes near the solar surface. Time series recorded by the IMaX instrument aboard the {\sc Sunrise} observatory reveal solar oscillations at high…

White-light flares (WLFs) are crucial for understanding the energy transport and heating processes in the lower solar atmosphere. Systematic studies are highly necessary. However, most WLFs are very weak and difficult to detect. To address…

Thermal changes in coronal loops are well-studied, both in quiescent active regions and in flaring scenarios. However, relatively little attention has been paid to loop emission in the hours before the onset of a solar flare; here, we…

Light echoes of stellar flares provide an intriguing option for exploring protoplanetary disks in young stellar systems. Previous work on light echoes of circumstellar disks made use of delta-function flares for modeling. We present a new…

Tsinghua University-Ma Huateng Telescopes for Survey (TMTS) aims to detect fast-evolving transients in the Universe, which has led to the discovery of thousands of short-period variables and eclipsing binaries since 2020. In this paper, we…

We present an investigation into an apparent relationship between white-light coronal brightness and the kinematics of flare-associated CMEs. Using a unique dataset known as the LASCO Coronal Brightness Index (CBI), we conduct a study that…

The prediction of solar flares is of practical and scientific interest; however, many machine learning methods used for this prediction task do not provide the physical explanations behind a model's performance. We made use of two recently…

Coronal mass ejections (CMEs) are often accompanied by coronal dimming evident in extreme ultraviolet (EUV) and soft X-ray observations. The locations of dimming are sometimes considered to map footpoints of the erupting flux rope. As the…

Context. The wings of the Ca II H and K lines provide excellent photospheric temperature diagnostics. At the Swedish 1-meter Solar Telescope the blue wing of Ca II H is scanned with a narrowband interference filter mounted on a rotation…

Knowledge of solar irradiance variability is critical to Earth's climate models and understanding the solar influence on Earth's climate. Direct solar irradiance measurements are only available since 1978. Reconstructions of past…

In the present work we study Hinode/EIS observations of an active region taken before, during and after a small C2.0 flare in order to monitor the evolution of the magnetic field evolution and its relation to the flare event. We find that…

We analyze spectra of a slipping flare kernel observed during the 2015 June 22 M6.5-class flare by the Interface Region Imaging Spectrograph (IRIS). During the impulsive and peak phases of the flare, loops exhibiting an apparent slipping…

We present the results of a search for stellar flares from stars neighbouring the target sources in the Kepler short cadence data. These flares have been discarded as contaminants in previous surveys and therefore provide an unexplored…

Many core-collapse supernova progenitors are presumed to be in binary systems. If a star explodes in a binary system, the early supernova light curve can be brightened by the collision of the supernova ejecta with the companion star. The…

The interacting binary Eta Carinae remains one of the most enigmatic massive stars in our Galaxy despite over four centuries of observations. In this work, its light curve from the ultraviolet to the near-infrared is analysed using…

Context: On 2022 May 4, an M5.7 flare erupted in the active region NOAA 13004, which was the target of a coordinated campaign between GREGOR, IRIS, Hinode, and ground-based instruments at the Ond\v{r}ejov observatory. A flare kernel located…

We study the chromospheric LOS velocities during the GOES M3.2 flare (SOL2013-05-17T08:43) using simultaneous spectroscopic data of the He I 1083.0 nm triplet and Ca II 854.2 nm line. A filament was present in the flaring area. The…