Various Features of the X-class White-light Flares in Super Active Region NOAA 13664
Autor: | Ying Li, Xiaofeng Liu, Zhichen Jing, Wei Chen, Qiao Li, Yang Su, De-Chao Song, M. D. Ding, Li Feng, Hui Li, Weiqun Gan |
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Jazyk: | angličtina |
Rok vydání: | 2024 |
Předmět: | |
Zdroj: | The Astrophysical Journal Letters, Vol 972, Iss 1, p L1 (2024) |
Druh dokumentu: | article |
ISSN: | 2041-8213 2041-8205 |
DOI: | 10.3847/2041-8213/ad6d6c |
Popis: | Super active region NOAA 13664 produced 12 X-class flares (including the largest one so far, an occulted X8.7 flare, in solar cycle 25) during 2024 May 8–15, and 11 of them are identified as white-light flares. Here we present various features of these X-class white-light flares observed by the White-light Solar Telescope (WST) on board the Advanced Space-based Solar Observatory and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. It is found that both the white-light emissions at WST 3600 Å (Balmer continuum) and HMI 6173 Å (Paschen continuum) show up in different regions of the sunspot group in these flares, including outside the sunspots and within the penumbra and umbra of the sunspots. They exhibit a point-, ribbon-, loop-, or ejecta-like shape, which can come from flare ribbons (or footpoints), flare loops, and plasma ejecta depending on the perspective view. The white-light duration and relative enhancement are measured and both parameters for 3600 Å emission have greater values than those for 6173 Å emission. It is also found that these white-light emissions are cospatial well with the hard X-ray (HXR) sources in the on-disk flares but have some offsets with the HXR emissions in the off-limb flares. In addition, it is interesting that the 3600 and 6173 Å emissions show different correlations with the peak HXR fluxes, with the former one more sensitive to the HXR emission. All these greatly help us understand the white-light flares of a large magnitude from a super active region on the Sun and also provide important insights into superflares on Sun-like stars. |
Databáze: | Directory of Open Access Journals |
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