Related papers: X-ray flaring from the young stars in CygnusOB2
We analyze new observations of superflares on G-stars discovered in the optical and near IR ranges with the Kepler mission. An evolution of solar-type activity is discussed. We give an estimate of the maximal total energy, $E_{tot} =…
We present our 500 pc distance-limited study of stellar fares using the Dark Energy Camera as part of the Deeper, Wider, Faster Program. The data was collected via continuous 20-second cadence g band imaging and we identify 19,914 sources…
We present an overview of K2 short cadence observations for 34 M dwarfs observed in Campaigns 1 - 9 which have spectral types between M0 - L1. All of the stars in our sample showed flares with the most energetic reaching $3\times10^{34}$…
Gamma-ray burst (GRB) X-ray light curves exhibit a variety of complex temporal structures, such as flares and plateaus. The origin of flares seen in many GRB early afterglows is still uncertain. Here, we analyze a sample of 89 GRBs, 61 of…
This work provides a statistical analysis of the massive star binary characteristics in the Cygnus OB2 Association using radial velocity information of 114 B3-O3 primary stars and orbital properties for the 24 known binaries. We compare…
Statistically analyzing Johnson UBVR observations of V1285 Aql during the three observing seasons, both activity level and behavior of the star are discussed in respect to obtained results. We also discuss the out-of-flare variation due to…
We analyzed the light curves of 1376 early-to-late, nearby M dwarfs to search for white-light flares using photometry from the All-Sky Automated Survey for Supernovae (ASAS-SN). We identified 480 M dwarfs with at least one potential flare…
Large-amplitude, high-luminosity soft X-ray flares were detected by the ROSAT All-Sky Survey in several galaxies with no evidence of Seyfert activity in their ground-based optical spectra. These flares had the properties predicted for a…
We present a catalog of 9017 X-ray sources identified in Chandra observations of a 2 by 0.8 degree field around the Galactic center. We increase the number of known X-ray sources in the region by a factor of 2.5. The catalog incorporates…
We used the Aladin Virtual Obsrvatory tool and High Resolution Imager ROSAT archival data to search for X-ray variability in scale of days in 23 young stars in the sigma Orionis cluster and a background galaxy. Five stars displayed…
In the study of stellar flares, traditional method of calculating total energy emitted in the continuum assumes the emission originating from a narrow chromospheric condensation region with a constant temperature of 10000 K and variable…
Stellar flares are powerful bursts of electromagnetic radiation triggered by magnetic reconnection in the chromosphere of stars, occurring frequently and intensely on active M dwarfs. While missions like TESS and Kepler have studied regular…
We present an analysis of seven flares detected from five RS CVn-type binaries (UZ Lib, \sigma Gem, \lambda And, V711 Tau and EI Eri) observed with XMM-Newton observatory. The quiescent state X-ray luminosities in the energy band of…
We search for unresolved X-ray emission from lensed sources in the FOV of 11 CLASH clusters with Chandra data. We consider the solid angle in the lens plane corresponding to a magnification $\mu>1.5$, that amounts to a total of ~100…
Mechanisms regulating the origin of X-rays in YSOs and the correlation with their evolutionary stage are under debate. Studies of the X-ray properties in young clusters allow to understand these mechanisms. One ideal target for this…
We present a catalog of 6266 solar flares detected by the X-Ray Solar Monitor onboard the Chandrayaan-2 lunar orbiter between 1.55 and 12.4 keV (1 and 8 \AA) from 2019 September 12 to 2022 November 4, including 1469 type A flares. The…
The supermassive black hole at the centre of the Galaxy flares at least daily in the infrared (IR) and X-ray bands, yet the process driving these flares is still unknown. So far detailed analysis has only been performed on a few bright…
We present simultaneous high-temporal and high-spectral resolution observations at optical and soft X-ray wavelengths of the nearby flare star CN Leo. During our observing campaign a major flare occurred, raising the star's instantaneous…
We report on \chandra observations of the central region of M31. By combining eight \chandra ACIS-I observations taken between 1999 and 2001, we have identified 204 X-ray sources within the central $\sim 17'\times17'$ region of M31, with a…
We improve the method proposed by Yao \emph{et al} (2003) to resolve the X-ray dust scattering halos of point sources. Using this method we re-analyze the Cygnus X-1 data observed with {\it Chandra} (ObsID 1511) and derive the halo radial…