English
Related papers

Related papers: YOHKOH remnants: partially occulted flares in hard…

200 papers

Recently, a number of peculiar flares have been reported, which demonstrate significant non-thermal particle signatures with a low, if any, thermal emission, that implies close association of the observed emission with the primary energy…

Previous studies have shown that the energy release mechanism of some solar flares follow the Standard magnetic-reconnection model, but the detailed properties of high-energy electrons produced in the flare are still not well understood. We…

Solar and Stellar Astrophysics · Physics 2015-07-15 Natsuha Kuroda , Haimin Wang , Dale E. Gary

Multi-instrument data sets of NOAA AR10938 on Jan. 16, 2007, (e.g., {\emph{Hinode}}, {\it{STEREO}}, {\it{GOES}}, {\it{MLSO}} and {\it{ISOON}} H$\alpha$) are utilized to study the fine structure and evolution of a magnetic loop system…

Solar and Stellar Astrophysics · Physics 2009-11-13 N. -E. Raouafi

We investigate the thermal properties of a solar flare by the observations of soft X-ray Telescope (XRT) on board Hinode and the Atmospheric Image Assembly on board the Solar Dynamics Observatory (SDO/AIA). Our analysis reveals a tenuous…

Solar and Stellar Astrophysics · Physics 2025-10-22 Xiaoyan Xie , Anna Chen , Crisel Suarez , Katharine K. Reeves , Soumya Roy , Christopher S. Moore , Nishu Karna , Joy Velasquez

We study the magnetic field structures of hard X-ray sources and flare ribbons of the M1.1 flare in active region NOAA 10767 on 2005 May 27. We have found in a nonlinear force-free field extrapolation, over the same polarity inversion line,…

Solar and Stellar Astrophysics · Physics 2015-06-03 Y. Guo , M. D. Ding , B. Schmieder , P. Démoulin , H. Li

We present the results of a search of the XMM-Newton public data archive for stellar X-ray flares. We find eight flaring sources for which we identify 7 optical counterparts. Three of these sources have distance estimates which allow us to…

Astrophysics · Physics 2009-11-10 Duncan Trenholme , Gavin Ramsay , Carl Foley

Magnetic-field reconnection is believed to play a fundamental role in magnetized plasma systems throughout the Universe1, including planetary magnetospheres, magnetars and accretion disks around black holes. This letter present extreme…

Solar and Stellar Astrophysics · Physics 2015-02-06 Yang Su , Astrid M. Veronig , Gordon D. Holman , Brian R. Dennis , Tongjiang Wang , Manuela Temmer , Weiqun Gan

The timing of 503 solar flares observed simultaneously in hard X-rays, soft X-rays and H-alpha is analyzed. We investigated the start and the peak time differences in different wavelengths, as well as the differences between the end of the…

Astrophysics · Physics 2015-06-24 A. Veronig , B. Vrsnak , M. Temmer , A. Hanslmeier

Solar eruptive events, including solar flares and coronal mass ejections (CMEs), are typically characterised by energetically significant X-ray emissions from flare-accelerated electrons and hot thermal plasmas. Occulted events, where the…

Solar and Stellar Astrophysics · Physics 2024-11-13 Laura A. Hayes , Säm Krucker , Hannah Collier , Daniel Ryan

Quasi-periodic oscillations of the hard X-ray (HXR) emission of the large flare of 2 November 1991 have been investigated using HXR light curves and soft X-ray and HXR images recorded by the {\sl Yohkoh} X-ray telescopes. The results of the…

Solar and Stellar Astrophysics · Physics 2015-06-15 Jerzy Jakimiec , Michal Tomczak

Spatially-resolved X-ray observations are the key to understanding electron acceleration in solar flares. Currently, the underlying processes that efficiently energize solar flare particles are poorly constrained. Abundant flare…

Solar and Stellar Astrophysics · Physics 2026-03-09 Morgan Stores , Natasha Jeffrey , Ewan Dickson , James McLaughlin , Eduard Kontar

The Neupert effect refers to the strong correlation between the soft X-ray (SXR) light curve and the time-integrated hard X-rays (HXR) or microwave flux, which is frequently observed in solar flares. In this article, we therefore utilized…

Solar and Stellar Astrophysics · Physics 2024-04-04 Dong Li , Hanyang Dong , Wei Chen , Yang Su , Yu Huang , Zongjun Ning

Solar flares are driven by release of the free magnetic energy and its conversion to other forms of energy -- kinetic, thermal, and nonthermal. Quantification of partitions between these energy components and their evolution is needed to…

Solar and Stellar Astrophysics · Physics 2023-08-02 Gregory D. Fleishman , Gelu M. Nita , Galina G. Motorina

Mercury mission MESSENGER's %(MErcury Surface, Space ENvironment, GEochemistry, and Ranging Solar Assembly for X-rays (SAX) observed almost 700 solar flares between May 28, 2007 and August 19, 2013, as cataloged by…

Solar and Stellar Astrophysics · Physics 2021-01-06 Erica Lastufka , Säm Krucker

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…

In this work we study the correlation between the soft (1.6--12.4 keV, mostly thermal) and the hard (20--40 and 60--80 keV, mostly non-thermal) X-ray emission in solar flares up to the most energetic events, spanning about 4 orders of…

Astrophysics · Physics 2009-11-13 C. Isola , F. Favata , G. Micela , H. S. Hudson

We report a statistical study of flares observed with the Soft X-ray Telescope (SXT) onboard Yohkoh in the year of 2000. We measure physical parameters of 77 flares, such as the temporal scale, the size, and the magnetic flux density and…

Astrophysics · Physics 2007-05-23 Kaori Nagashima , Takaaki Yokoyama

We investigate the X-ray and UV emission detected by RHESSI and TRACE in the context of a solar flare on the 16th November 2002 with the goal of better understanding the evolution of the flare. We analysed the characteristics of the X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-11 Hamish A. S. Reid , Nicole Vilmer , Guillaume Aulanier , Etienne Pariat

The disparate nature of thermal-nonthermal energy partition during flares, particularly during weak flares, is still an open issue. Following the Neupert effect, quantifying the relative yield of X-ray emission in different energy bands can…

Solar and Stellar Astrophysics · Physics 2024-02-06 Arun Kumar Awasthi , Tomasz Mrozek , Sylwester Kołomański , Michalina Litwicka , Marek Stęślicki , Karol Kułaga

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…