Related papers: X-Ray Superflares on CC Eri

Solar and stellar flares are powerful events which produce intense radiation across the electromagnetic spectrum. Multiwavelength observations are highly important for understanding the nature of flares, because different flare-related…

In this work we study the correlation between the soft (1.6--12.4 keV, mostly thermal) and the hard (20--40 and 60--80 keV, mostly non-thermal) X-ray emission in solar flares up to the most energetic events, spanning about 4 orders of…

We have calculated the H$\alpha$ and Ca {\sc ii} 8542 {\AA} line profiles based on four different atmospheric models, including the effects of nonthermal electron beams with various energy fluxes. These two lines have different responses to…

This paper presents the gamma-ray spectral and timing results from the long-term regular observations of Mrk 421 with the Large Area Telescope (LAT) onboard Fermi during 2008 August - 2023 August. We discerned six periods the relatively…

White-light flares are explosive phenomena accompanied by brightening of continuum from near-ultraviolet to optical, which occur on the Sun and stars. In order to investigate the mechanism of white-light flares, we carried out simultaneous…

The Solar X-ray Spectrometer (XSM) payload onboard Chandrayaan-2 provides disk-integrated solar spectra in the 1-15 keV energy range with an energy resolution of 180 eV (at 5.9 keV) and a cadence of 1~second. During the period from…

We present new phase-resolved H and K-band spectroscopy of the ultra-short period magnetic cataclysmic variable EF Eri in its current, prolonged ``low'' state obtained using NIRI on Gemini-North, and NIRSPEC on Keck II. These new data show…

We report on the detailed study of the 2008 October outburst from the anomalous X-ray pulsar (AXP) 1E 1547.0-5408 discovered through the Swift/Burst Alert Telescope (BAT) detection of SGR-like short X-ray bursts on 2008 October 3. The…

We present the temporal and spectral study of blazar PKS 0208-512, using recent flaring activity from November 2019 to May 2020, as detected by the Fermi-LAT observatory. The contemporaneous X-ray, optical/UV observations from…

Flare kernels are compact features located in the solar chromosphere that are the sites of rapid heating and plasma upflow during the rise phase of flares. An example is presented from a M1.1 class flare observed on 2011 February 16 07:44…

Temporal and spectral characteristics of X-ray emission from 60 flares of intensity $\ge$C class observed by Solar X-ray Spectrometer (SOXS) during 2003-2011 are presented. We analyse the X-ray emission observed in four and three energy…

We present the first results of our ongoing project conducting simultaneous multiwavelength observations of flares on nearby active M dwarfs. We acquired data of the nearby dM3.5e star EV Lac using 5 different observatories: NASA's…

An uncatalogued bright X-ray transient was detected with MAXI on November 9, 2024, named MAXI J1752$-$457. The NinjaSat X-ray observatory promptly observed the source from November 10 to 18 while the small angular separation from the Sun…

CW Eri is a detached eclipsing binary system of two F-type stars with an orbital period of 2.728 d. Light curves from two sectors of observations with the Transiting Exoplanet Survey Satellite (TESS) and previously published radial velocity…

We present a detailed multi-wavelength analysis and interpretation of the evolution of an M7.6 flare on October 24, 2003. The X-ray observations of the flare taken from the RHESSI spacecraft reveal two phases of the flare evolution. The…

The long gamma-ray burst GRB 060714 was observed to exhibit a series of five X-ray flares beginning ~70 s after the burst trigger T0 and continuing until T0 + ~200 s. The first two flares were detected by the Burst Alert Telescope (BAT) on…

The extreme solar and SEP event of 20 January 2005 is analyzed from two perspectives. Firstly, we study features of the main phase of the flare, when the strongest emissions from microwaves up to 200 MeV gamma-rays were observed. Secondly,…

Observations of solar flares with RHESSI have shown X-ray sources traveling along flaring loops, from the corona down to the chromosphere and back up. The 28 November 2002 C1.1 flare, first observed with RHESSI by Sui et al. 2006 and…

Spectroscopic observations in X-ray wavelengths provide excellent diagnostics of the temperature distribution in solar flare plasma. The Solar X-ray Monitor (XSM) onboard the Chandrayaan-2 mission provides broad-band disk integrated soft…

Context. Hard X-ray (HXR) spikes refer to fine time structures on timescales of seconds to milliseconds in high-energy HXR emission profiles during solar flare eruptions. Aims. We present a preliminary statistical investigation of temporal…