相关论文: X-Ray Flaring on the dMe Star, Ross 154

We present evidence from Beppo-SAX and XMM-Newton of extreme X-ray variability in the high luminosity radio-quiet quasar PDS 456, the most luminous known AGN at z<0.3. Repeated X-ray flaring is found in PDS 456, over the duration of the 340…

We present our search for flares from M dwarf stars in the SkyMapper Southern Survey DR1, which covers nearly the full Southern hemisphere with six-filter sequences that are repeatedly observed in the passbands $uvgriz$. This allows us to…

Coronal mass ejections (CMEs), often associated with flares, are the most powerful magnetic phenomena occurring on the Sun. Stars show magnetic activity levels up to 10^4 times higher, and CME effects on stellar physics and circumstellar…

During an XMM-Newton observation, the eclipsing polar UZ For was found in a peculiar state with an extremely low X-ray luminosity and occasional X-ray and UV flaring. For most of the observation, UZ For was only barely detected in X-rays…

I present an optical characterization of the Galactic X-ray transient source MAXI J1957$+$032. This system flares by a factor of $\gtrsim10^{4}$ every few-hundred days, with each flare lasting $\sim5$ days. I identify its quiescent…

According to activity-rotation relations, rapid rotators are expected to show high levels of magnetic activity. However, recent studies with TESS have found Ultra Fast Rotating (UFR) M dwarfs with periods $<1$ d displaying low levels of…

Detailed studies of the Sun have shown that sunspots and solar flares are closely correlated. Photometric data from Kepler/K2 has allowed similar studies to be carried out on other stars. Here, we utilise TESS photometric 2-min cadence of…

In this study we present the analysis of six solar flare events that occurred in 2022, using new data from the third-generation Miniature X-Ray Solar Spectrometer (MinXSS), also known as the Dual-zone Aperture X-ray Solar Spectrometer…

We analyse the 30 October, 2004, X1.2/SF solar event that occurred in AR 10691 (N13 W18) at around 11:44 UT. Observations at 212 and 405 GHz of the Solar Submillimeter Telescope (SST), with high time resolution (5 ms), show an intense…

The Neutron Star X-ray binary Sco X-1 is one of the brightest Z-type sources in our Galaxy, showing frequent periods of flaring activity and different types of relativistic outflows. Observations with RXTE have shown that the strongest…

The GOES X1 flare SOL2014-10-25T17:08:00 was a three-ribbon solar flare observed with IRIS in the near and far ultraviolet. One of the flare ribbons crossed a sunspot umbra, producing a dramatic, $\sim1000$% increase in the near-ultraviolet…

The extensive observations done by the X-ray telescope onboard Neil Gehrels Swift observatory has revealed the presence of late time flares concurrent with the decaying afterglow emission. However, the origin of these flares are elusive. In…

We report on two millimeter flares detected by ALMA at 220 GHz from AU Mic, a nearby M dwarf. The larger flare had a duration of only $\sim35$ sec, with peak $L_{R}=2\times10^{15}$ erg s$^{-1}$ Hz$^{-1}$, and lower limit on linear…

Most M dwarfs show higher chromospheric activity, often exceeding solar levels. Characterizing stellar activity is essential, particularly since these stars are prime targets in the search for habitable exoplanets. We investigate the…

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 perform a study of stellar flares for the 24,809 stars observed with 2 minute cadence during the first two months of the TESS mission. Flares may erode exoplanets' atmospheres and impact their habitability, but might also trigger the…

The rapidly varying (~10 minute timescale) non-thermal X-ray emission observed from Sgr A* implies that particle acceleration is occuring close to the event horizon of the supermassive black hole. The TeV gamma-ray source HESS J1745-290 is…

A study of the six largest coronal X-ray flares in the Chandra archive is presented. The flares were observed on II Peg, OU And, Algol, HR 1099, TZ CrB and CC Eri, all with the High Energy Transmission Grating spectrometer (HETG) and the…

Based on a sample of 1114 flares observed simultaneously in hard X-rays (HXR) by the BATSE instrument and in soft X-rays (SXR) by GOES, we studied several aspects of the Neupert effect and its interpretation in the frame of the…

M dwarfs are known to flare on timescales from minutes to hours, with flux increases of several magnitudes in the blue/near-UV. These frequent, powerful events, which are caused by magnetic reconnection, will have a strong observational…