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Related papers: ZIMPOL detects scattering polarization in He I D$_…

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He I D3 line has a unique response to the flare impact on the low solar atmosphere and can be a powerful diagnostic tool for energy transport processes. Using images obtained from the recently digitized films of Big Bear Solar Observatory,…

Solar and Stellar Astrophysics · Physics 2015-06-16 Chang Liu , Yan Xu , Na Deng , Jeongwoo Lee , Jifeng Zhang , Debi Prasad Choudhary , Haimin Wang

Context. Magnetic reconnection during flares takes place in the corona but a substantial part of flare energy is deposited in the chromosphere. However, high-resolution spectro-polarimetric chromospheric observations of flares are very…

Solar and Stellar Astrophysics · Physics 2019-01-09 Tine Libbrecht , Jaime de la Cruz Rodriguez , Sanja Danilovic , Jorrit Leenaarts , Hiva Pazira

We performed statistical and event studies of linear polarization in the H$\alpha$ line during solar flares. The statistical study revealed that, among 71 H$\alpha$ flares analyzed, including 64 GOES flares, only one event shows significant…

Solar and Stellar Astrophysics · Physics 2019-02-20 Tomoko Kawate , Yoichiro Hanaoka

This letter reports on a set of full-Stokes spectropolarimetric observations in the near infrared He I 10830 A spectral region covering the pre-, flare, and post-flare phases of an M3.2 class solar flare. The flare originated on 2013 May 17…

Solar and Stellar Astrophysics · Physics 2015-06-23 C. Kuckein , M. Collados , R. Manso Sainz

We present novel spectropolarimetric observations of the hydrogen H$\alpha$ line taken with the Z\"urich Imaging Polarimeter (ZIMPOL) at the Gregory Coud\'e Telescope of the Istituto Ricerche Solari Locarno (IRSOL). The linear polarization…

Solar and Stellar Astrophysics · Physics 2022-03-30 J. Jaume Bestard , J. Trujillo Bueno , M. Bianda , J. Štěpán , R. Ramelli

High sensitivity observations of Halpha polarization of 30 flares of different sizes and disk positions are reported. Both filter and spectrographic techniques have been used. The ZIMPOL system eliminates spurious polarizations due to…

Astrophysics · Physics 2009-11-10 M. Bianda , A. O. Benz , J. O. Stenflo , G. Kueveler , R. Ramelli

Between 2017 and 2024, the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory has observed numerous white-light solar flares (WLFs). HMI spectro-polarimetric observations of certain WLFs, in particular the X9.3…

Solar and Stellar Astrophysics · Physics 2025-07-02 Samuel Granovsky , Alexander G. Kosovichev , Viacheslav M. Sadykov , Graham S. Kerr , Joel C. Allred

A large set of high precision full-Stokes spectropolarimetric observations of prominences in He-D3, Halpha and Hbeta lines has been recorded with the ZIMPOL polarimeter at the Gregory-Coude Telescope in Locarno. The observational technique…

Solar and Stellar Astrophysics · Physics 2009-06-15 R. Ramelli , M. Bianda , J. Trujillo Bueno , L. Merenda , J. O. Stenflo

The Sr~{\sc i} 4607~\AA\ spectral line shows one of the strongest scattering polarization signals in the visible solar spectrum. The amplitude of this polarization signal is expected to vary at granular spatial scales, due to the combined…

Scattering polarization in the Sr I 4607.3 \AA \ line observed with high resolution is an important diagnostic of the Sun's atmosphere and magnetism at small spatial scales. At present, spatially resolved observations of this diagnostic are…

Solar and Stellar Astrophysics · Physics 2018-11-28 F. Zeuner , A. Feller , F. A. Iglesias , S. K. Solanki

Sr I 4607\AA spectral line shows one of the strongest scattering polarization signals in the visible solar spectrum. The amplitudes of these signals are expected to vary at granular spatial scales. This variation can be due to changes in…

The near-Earth space weather is driven by the quick release of magnetic free energy in the solar corona. Probing this extremely hot and rarified region of the extended solar atmosphere requires modeling the polarization of forbidden and…

Solar and Stellar Astrophysics · Physics 2021-11-03 Supriya Hebbur Dayananda , Javier Trujillo Bueno , Ángel de Vicente , Tanausú del Pino Alemán

The first significant sunquake event of Solar Cycle 25 was observed during the X1.5 flare of May 10, 2022, by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory. We perform a detailed spectro-polarimetric…

Solar and Stellar Astrophysics · Physics 2023-09-15 Alexander G. Kosovichev , Viacheslav M. Sadykov , John T. Stefan

A large set of high precision full-Stokes spectropolarimetric observations of the He-D3 line in spicules has been recorded with the ZIMPOL polarimeter at the Gregory-Coude Telescope in Locarno. The observational technique allow us to obtain…

Solar and Stellar Astrophysics · Physics 2010-11-26 R. Ramelli , M. Bianda , L. Merenda , J. Trujillo Bueno

We report the results of a high temporal resolution spectroscopic monitoring of the flare star AD Leo. During 4 nights, more than 600 spectra were taken in the optical range using the Isaac Newton Telescope (INT) and the Intermediate…

This study presents a C3.0 flare observed by the BBSO/GST and IRIS, on 2018-May-28 around 17:10 UT. The Near Infrared Imaging Spectropolarimeter (NIRIS) of GST was set to spectral imaging mode to scan five spectral positions at $\pm$ 0.8…

Solar and Stellar Astrophysics · Physics 2022-01-19 Yan Xu , Xu Yang , Graham S. Kerr , Vanessa Polito , Viacheslav M. Sadykov , Ju Jing , Wenda Cao , Haimin Wang

We present an exceptional data set acquired with the Vacuum Tower Telescope (Tenerife, Spain) covering the pre-flare, flare, and post-flare stages of an M3.2 flare. The full Stokes spectropolarimetric observations were recorded with the…

Solar and Stellar Astrophysics · Physics 2015-02-20 C. Kuckein , M. Collados , R. Manso Sainz , A. Asensio Ramos

Aims: This work aims to identify the mechanism driving pulsations in hard X-ray (HXR) and microwave emission during solar flares. Here, by using combined HXR and microwave observations from Solar Orbiter/STIX and EOVSA we investigate an…

Solar and Stellar Astrophysics · Physics 2024-05-01 Hannah Collier , Laura A. Hayes , Sijie Yu , Andrea F. Battaglia , William Ashfield , Vanessa Polito , Louise K. Harra , Säm Krucker

This work aims to identify the relevant physical processes in shaping the intensity and polarization patterns of the solar K I D lines through spectral syntheses, placing particular emphasis on the D2 line. The theoretical Stokes profiles…

Solar and Stellar Astrophysics · Physics 2022-08-26 Ernest Alsina Ballester

We analyze spectropolarimetric data of the He I 1083~nm multiplet ($1s2s~^3\!S_1 - 1s2p~^3\!P^o_{2,1,0}$) during the X1 flare SOL2014-03-29T17:48, obtained with the Facility Infrared Spectrometer (FIRS) at the Dunn Solar Telescope. While…

Solar and Stellar Astrophysics · Physics 2015-11-02 Philip G. Judge , Lucia Kleint , Alberto Sainz-Dalda
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