During solar flares, magnetic energy can be converted into electromagneticradiation from radio waves to $gamma$ rays. Enhancements in the continuum atvisible wavelengths give rise to white-light flares, as well as continuumenhancements in the FUV and NUV passbands. In addition, the strong energyrelease in these events can lead to the rearrangement of the magnetic field atthe photospheric level, causing morphological changes in large and stablemagnetic structures like sunspots. In this context, we describe observationsacquired by satellite instruments (IRIS, SDO/HMI, Hinode/SOT) and ground-basedtelescopes (ROSA/DST) during two consecutive C7.0 and X1.6 flares occurred inactive region NOAA 12205 on 2014 November 7. The flare was accompanied by aneruption. The results of the analysis show the presence of continuumenhancements during the evolution of the events, observed both in ROSA imagesand in extitIRIS spectra. In the latter, a prominent blue-shifted componentis observed at the onset of the eruption. We investigate the role played by theevolution of the $delta$ sunspots of the active region in the flaretriggering, and finally we discuss the changes in the penumbrae surroundingthese sunspots as a further consequence of these flares.

Continuum enhancements, line profiles and magnetic field evolution during consecutive flares

Francesca Zuccarello
Primo
Conceptualization
;
Salvo L. Guglielmino
Secondo
Investigation
;
Vincenzo Capparelli
Investigation
;
Mariachiara Falco;Mariarita Murabito
2020

Abstract

During solar flares, magnetic energy can be converted into electromagneticradiation from radio waves to $gamma$ rays. Enhancements in the continuum atvisible wavelengths give rise to white-light flares, as well as continuumenhancements in the FUV and NUV passbands. In addition, the strong energyrelease in these events can lead to the rearrangement of the magnetic field atthe photospheric level, causing morphological changes in large and stablemagnetic structures like sunspots. In this context, we describe observationsacquired by satellite instruments (IRIS, SDO/HMI, Hinode/SOT) and ground-basedtelescopes (ROSA/DST) during two consecutive C7.0 and X1.6 flares occurred inactive region NOAA 12205 on 2014 November 7. The flare was accompanied by aneruption. The results of the analysis show the presence of continuumenhancements during the evolution of the events, observed both in ROSA imagesand in extitIRIS spectra. In the latter, a prominent blue-shifted componentis observed at the onset of the eruption. We investigate the role played by theevolution of the $delta$ sunspots of the active region in the flaretriggering, and finally we discuss the changes in the penumbrae surroundingthese sunspots as a further consequence of these flares.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/20.500.11769/373963
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