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Related papers: Microflaring of a solar Bright point

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A small flare ribbon above a sunspot umbra in active region 12205 was observed on November 7, 2014, at 12:00 UT in the blue imaging channel of the 1.5 m GREGOR telescope, using a 1 A Ca II H interference filter. Context observations from…

A long ($>100,000$ seconds) observation of the bright BL Lac object PKS 2155-304 has been carried out with the Narrow Field Instruments of the BeppoSAX satellite as part of the Science Verification Phase. The source was detected between 0.1…

Astrophysics · Physics 2007-05-23 P. Giommi et al

We have analysed in detail the discovery measurements of the X-ray burster SAX J1750.8-2900 by the Wide Field Cameras on board BeppoSAX in spring 1997, at a position ~1.2 degrees off the Galactic Centre. The source was in outburst on March…

It is generally believed that sunspots are the emergent part of magnetic flux tubes in the solar interior. These tubes are created at the base of the convection zone and rise to the surface due to their magnetic buoyancy. The motion of…

Solar and Stellar Astrophysics · Physics 2015-05-14 Franck Plunian , Graeme Sarson , Rodion Stepanov

On modern satellite observations of the Sun in the continuum with high spatial resolution, as well as on high-quality ground observations, a large number of small dark areas can be observed. These regions have no penumbra, have a contrast…

Solar and Stellar Astrophysics · Physics 2022-06-08 Andrey G. Tlatov

We present multi-wavelength measurements of the thermal, chemical, and cloud contrasts associated with the visibly dark formations (also known as 5-$\mu$m hot spots) and intervening bright plumes on the boundary between Jupiter's Equatorial…

Magnetic elements on the quiet sun are buffeted by convective flows that cause lateral motions on timescales of minutes. The magnetic elements can be observed as bright points (BPs) in the G band at 4305 {\AA}. We present observations of…

Astrophysics · Physics 2009-11-07 P. Nisenson , A. A. van Ballegooijen , A. G. de Wijn , P. Sutterlin

{We report on the first of a series of studies on coronal bright points investigating the physical mechanism that generates these phenomena.} {The aim of this paper is to understand the magnetic-field structure that hosts the bright…

Solar and Stellar Astrophysics · Physics 2017-10-11 K. Galsgaard , M. S. Madjarska , F. Moreno-Insertis , Z. Huang , T. Wiegelmann

Small-scale magnetic fields can be observed on the Sun in high resolution G-band filtergrams as magnetic bright points (MBPs). We study Hinode/ Solar Optical Telescope (SOT) longitude and latitude scans of the quiet solar surface taken in…

Solar and Stellar Astrophysics · Physics 2012-12-07 D. Utz , A. Hanslmeier , A. Veronig , O. Kühner , R. Muller , J. Jurčák , B. Lemmerer

We have made high-resolution, high-sensitivity dynamic spectra of a sample of strong pulsars at 430 MHz with the Arecibo radiotelescope. For 4 pulsars we find faint but sharply delineated features in the secondary spectra. These are…

Aims: This paper aims to demonstrate the importance of short-exposure extreme ultraviolet (EUV) observations of solar flares in the study of particle acceleration, heating and energy partition in flares. This work highlights the…

The slowly positively drifting bursts (SPDBs) are rarely observed in radio emission of solar flares. To understand how the SPDBs are generated, we studied the radio observations at 600--5000 MHz together with the imaging observations made…

Solar and Stellar Astrophysics · Physics 2024-08-23 Alena Zemanová , Marian Karlický , Jana Kašparová , Jaroslav Dudík , Ján Rybák

X-ray observations of the Sun led Eugene Parker to propose nanoflares as the basic energy-release units that heat the solar corona. Decades later, Solar Orbiter's Extreme Ultraviolet Imager (HRIEUV), operating halfway between Earth and the…

We present simultaneous X-ray and spectral ultraviolet (UV) observations of strikingly-coherent oscillations in emission from a coronal looptop and fan structure, during the impulsive phase of a long-duration M-class solar flare. The 50 s…

Solar and Stellar Astrophysics · Physics 2024-11-06 Ryan J. French , Laura A. Hayes , Maria D. Kazachenko , Katharine K. Reeves , Chengcai Shen , Juraj Lörinčík

The Sun provides an excellent natural laboratory for nonlinear phenomena. We use motions of magnetic bright points on the solar surface, at the smallest scales yet observed, to study the small scale dynamics of the photospheric plasma. The…

Astrophysics · Physics 2009-11-06 J. K. Lawrence , A. C. Cadavid , A. Ruzmaikin , T. E. Berger

In this note, we consider radio characteristics of three proton flares that caused discrete enhancements of solar energetic particles (SEPs) near Earth. The analysis confirmed that the flux density and frequency spectrum of microwave…

Solar and Stellar Astrophysics · Physics 2018-02-02 I. M. Chertok

Solar flares are known to release a large amount of energy into accelerating electrons. Studying small timescale ($\leq$ 2s) fluctuations in nonthermal X-ray flux offers the opportunity to probe the nature of those acceleration mechanisms.…

Solar and Stellar Astrophysics · Physics 2020-11-11 Trevor Knuth , Lindsay Glesener

Realistic 3D radiative MHD simulations reveal the magneto-convective processes underlying the formation of the photospheric fine structure of sunspots, including penumbral filaments and umbral dots. Here we provide results from a…

Solar and Stellar Astrophysics · Physics 2015-05-14 L. Bharti , B. Beeck , M. Schuessler

The expansion with height of the solar photospheric magnetic field and the plasma flows is investigated for three isolated bright points (BPs). The BPs were observed simultaneously with 3 instruments at the GREGOR telescope: (1) filtergrams…

Solar and Stellar Astrophysics · Physics 2019-10-09 Christoph Kuckein

Stellar spots may in some cases produce radial velocity (RV) signatures similar to those of exoplanets. To further investigate the impact of spots, we aim at studying the detectability of Earth mass planets in the habitable zone (HZ) of…

Earth and Planetary Astrophysics · Physics 2015-05-14 A. -M. Lagrange , M. Desort , N. Meunier