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Related papers: NuSTAR observations of a repeatedly microflaring a…

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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…

Solar and Stellar Astrophysics · Physics 2021-05-12 Alexey A. Kuznetsov , Dmitrii Y. Kolotkov

Small-scale magnetic reconnection processes, in the form of nanoflares, have become increasingly hypothesized as important mechanisms for the heating of the solar atmosphere, for driving propagating disturbances along magnetic field lines…

Accurate measurements of magnetic and velocity fields in and around solar active regions are key to unlocking the mysteries of the formation and the decay of sunspots. High spatial resolution image and spectral sequences with a high cadence…

Abridged. We observed the 40 Myr old star DS Tuc A with XMM-Newton and recorded two X-ray bright flares, with the second event occurring about 12 ks after the first one. Their duration from the rise to the end of the decay was of about 8-10…

Solar and Stellar Astrophysics · Physics 2022-10-26 I. Pillitteri , C. Argiroffi , A. Maggio , G. Micela , S. Benatti , F. Reale , S. Colombo , S. J. Wolk

We present the analysis of the X-ray data of the young active star HD35850 obtained with ASCA and ROSAT. Our main goal was to see if there is a difference in the elemental abundances of active stars between young and more evolved objects. A…

Astrophysics · Physics 2007-05-23 G. Tagliaferri , S. Covino , T. A. Fleming , M. Gagnè , R. Pallavicini , F. Haardt , Y. Uchida

During its commissioning phase in 2020, the Spectrometer/Telescope for Imaging X-rays (STIX) on board the Solar Orbiter spacecraft observed 69 microflares. The two most significant events from this set (of GOES class B2 and B6) were…

Solar and Stellar Astrophysics · Physics 2022-03-14 J. Saqri , A. M. Veronig , A. Warmuth , E. C. M. Dickson , A. F. Battaglia , T. Podladchikova , H. Xiao , M. Battaglia , G. J. Hurford , S. Krucker

The Sun offers a convenient nearby laboratory to study the physical processes of particle acceleration and impulsive energy release in magnetized plasmas that occur throughout the universe, from planetary magnetospheres to black hole…

Solar and Stellar Astrophysics · Physics 2011-05-13 Amir Caspi

We report results of a spectral and timing analysis of the poorly studied transient X-ray pulsar 2S 1553-542 using data collected with the NuSTAR and Chandra observatories and the Fermi/GBM instrument during an outburst in 2015. Properties…

High Energy Astrophysical Phenomena · Physics 2016-01-27 Sergey S. Tsygankov , Alexander A. Lutovinov , Roman A. Krivonos , Sergey V. Molkov , Peter J. Jenke , Mark H. Finger , Juri Poutanen

JWST/MIRI has sharpened our infrared eyes toward the star formation process. This paper presents the first mid-infrared detection of gaseous SO$_2$ emission in an embedded low-mass protostellar system. MIRI-MRS observations of the low-mass…

Superflares on solar-type stars has been a rapidly developing field ever since the launch of $\it Kepler$. Over the years, there have been several studies investigating the statistics of these explosive events. In this study, we present a…

Solar and Stellar Astrophysics · Physics 2020-04-22 Lauren Doyle , Gavin Ramsay , J. Gerard Doyle

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…

We report results from the spectro-timing analysis of the atoll source 4U 1636$-$536 observed with NuSTAR and AstroSat during its hard spectral state. In three observations of 207 ks total exposure, we identify 31 thermonuclear X-ray bursts…

High Energy Astrophysical Phenomena · Physics 2022-08-03 Pinaki Roy , Aru Beri , Aditya S. Mondal

We present temporal and spectral characteristics of X-ray flares observed from six late-type G-K active dwarfs (V368 Cep, XI Boo, IM Vir, V471 Tau, CC Eri and EP Eri) using data from observations with the XMM-Newton observatory. All the…

Astrophysics · Physics 2009-11-13 J. C. Pandey , K. P. Singh

Even in the absence of resolved flares, the corona is heated to several million degrees. However, despite its importance for the structure, dynamics, and evolution of the solar atmosphere, the origin of this heating remains poorly…

Stellar flares are potent drivers of atmospheric evolution on orbiting exoplanets, primarily through extreme ultraviolet (EUV) and soft X-ray (XUV) irradiation. However, the contribution of hard X-rays (HXR; 3--20 keV)-which penetrate…

We report the discovery of 3.76-s pulsations from a new burst source near Sgr A* observed by the NuSTAR Observatory. The strong signal from SGR J1745-29 presents a complex pulse profile modulated with pulsed fraction 27+/-3 % in the 3-10…

The source GS~1826-24 is a neutron star low mass X-ray binary known as the 'clocked burster' because of its extremely regular bursting behavior. We report on the detection of a long type-I X-ray burst from this source. We perform a detailed…

High Energy Astrophysical Phenomena · Physics 2025-08-21 Aditya S. Mondal , Mayukh Pahari , Gulab C. Dewangan

We present the multi epoch spectral analysis of HE 0436-4717, a bright Seyfert 1 galaxy serendipitously observed by the high energy satellite NuSTAR four times between December 2014 and December 2015. The source flux shows modest…

Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal loop-top source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their…

The Interface Region Imaging Spectrometer (IRIS) is the first solar instrument to observe $\sim 10$ MK plasma at subarcsecond spatial resolution through imaging spectroscopy of the Fe XXI $\lambda$1354.1 forbidden line. IRIS observations of…

Solar and Stellar Astrophysics · Physics 2015-06-23 Peter Young , Hui Tian , Sarah Jaeggli
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