Narang, Nancy

Seminar presented at Royal Observatory of Belgium on 2024-12-16

Abstract: The extreme-ultraviolet (EUV) brightenings identified by Solar Orbiter (SolO), commonly known as campfires, are the smallest detected, to date, transient brightenings or bursts observed in the non-active regions of the lower solar corona. Campfires have been proposed to be the finest-scale members of the nanoflare family. Our understanding about the role of campfires in coronal heating stands elusive due to the absence of extensive statistical studies. In this talk I will highlight the results from the statistical analysis of campfires by using the highest possible resolution observations obtained by the Extreme Ultraviolet Imager (EUI) onboard SolO. We use observations in 17.4 nm passband of the High Resolution EUV Imager (HRIEUV ) of EUI obtained during the closest perihelia of SolO in the years of 2022 and 2023. SolO being at a distance 0.29 AU from the Sun, these observations have exceptionally high pixel resolution of 105 km with a fast cadence of 3 seconds. We estimate that about 4000 campfires appear per second on the whole Sun. Considering the HRIEUV bandpass that is most sensitive to the 1 MK plasma, the increasingly high number of campfires at smaller spatial and temporal scales over the quiet-Sun regions make them one of the contributors for the quiet-Sun coronal heating.

Keyword(s): EUI ; Solar Orbiter ; EUV Brightenings ; Nanoflares ; Magnetic Reconnection
Funding: B2/223/P1/CLOSE-UP