Related papers: Exploring the origin of multi-periodic pulsations …
Quasi-periodic pulsations (QPPs) appear to be a common feature observed in the light curves of both solar and stellar flares. However, their quasi-periodic nature, along with the fact that they can be small in amplitude and short-lived,…
We present a comprehensive timing analysis on the Be/X-ray binary pulsar RX J0440.9+4431 using observations from \textit{NICER} and \textit{Insight}-HXMT during the 2022--2023 outburst. The power density spectrum (PDS) of RX J0440.9+4431…
Most studies of quasi-periodic pulsations in solar flares have identified characteristic periods in the 5 - 300s range. Due to observational limitations there have been few attempts to probe the < 5s period regime and understand the…
On the 29 March 2014 NOAA active region (AR) 12017 produced an X1 flare which was simultaneously observed by an unprecedented number of observatories. We have investigated the pre-flare period of this flare from 14:00 UT until 19:00 UT…
X-ray Quasi-Periodic Eruptions (QPEs) are a recently discovered phenomenon associated with supermassive black holes at the centers of galaxies. They are high amplitude soft X-ray flares that recur on timescales of hours, but what causes…
A phenomenological relationship between oscillations in a sunspot and quasi-periodic pulsations in flaring energy releases at an active region above the sunspot, is established. The analysis of the microwave emission recorded by the…
Context. QPPs are usually detected as spatial displacements of coronal loops in imaging observations or as periodic shifts of line properties in spectroscopic observations. They are often applied for remote diagnostics of magnetic fields…
We report the discovery of a {recurrent} quasi-periodic pulsation (QPP) in the late-M dwarf GJ 3512 (M5.5V) using multiple TESS datasets. A strong signal with a period of 70-100 minutes was detected in wavelet analyses of the two-minute…
``Quasi-periodic eruptions'' (QPE) are recurrent nuclear transients with periods of several hours to almost a day, which thus far have been detected exclusively in the X-ray band. We have shown that many of the key properties of QPE flares…
We study a blowout jet that occurs at the west limb of the Sun on August 29$^{th}$, 2014 using high-resolution imaging/spectroscopic observations provided by SDO/AIA and IRIS. An inverse $\gamma$-shape flux-rope appears before the jet{--}…
Since their discovery by SDO/AIA in EUV, rapid (phase speeds of 1000 km/s), quasi-periodic, fast-mode propagating wave trains (QFPs) have been observed accompanying many solar flares. They typically propagate in funnel-like structures…
We studied a solar flare with pronounced quasi-periodic pulsations detected in the microwave, X-ray, and radio bands. We used the methods of correlation, Fourier, and wavelet analyses to examine the temporal fine structures and…
On 2011 May 30, quasi-periodic fast propagating (QFP) magnetosonic waves accompanied by a C2.8 flare were directly imaged by the Atomospheric Imaging Assembly instrument on board the Solar Dynamics Observatory. The QFP waves successively…
We have discovered rapid Quasi Periodic Oscillations (QPOs) in RXTE/PCA measurements of the pulsating tail of the 27th December 2004 giant flare of SGR 1806-20. QPOs at about 92.5Hz are detected in a 50s interval starting 170s after the…
We present the highly significant detection of a quasi-periodic flux modulation with a period of 22.2 min seen in the X-ray data of the Sgr A* flare of 2004 August 31. This flaring event, which lasted a total of about three hours, was…
We have performed a timing and spectral analysis of the X-ray pulsar SWIFT J1626.6-5156 during a major X-ray outburst in order to unveil its nature and investigate its flaring activity. Epoch- and pulse-folding techniques were used to…
Two different mechanisms may act to induce quasi-periodic pulsations (QPP) in whole-disk observations of stellar flares. One mechanism may be magneto-hydromagnetic (MHD) forces and other processes acting on flare loops as seen in the Sun.…
Super active region NOAA 13664 produced 12 X-class flares (including the largest one, an occulted X8.7 flare, in solar cycle 25 so far) during 2024 May 8-15 and 11 of them are identified as white-light flares. Here we present various…
The observational analysis is performed to study the excitation mechanism and the propagation properties of a quasi-periodic fast-propagating (QFP) magnetosonic wave. The QFP wave was associated with the eruption of a nearby mini-filament…
Flares are powerful events ignited by a sudden release of magnetic energy. With the aim of studying flares in the 125-Myr-old stars in the Pleiades observed simultaneously in optical and X-ray light, we obtained new XMM-Newton observations…