Ref: SCART-2022-0037

Propagating brightenings in small loop-like structures in the quiet-Sun corona: Observations from Solar Orbiter/EUI

Mandal, Sudip ; Peter, Hardi ; Pradeep Chitta, Lakshmi ; Solanki, Sami K. ; Aznar Cuadrado, Regina ; Teriaca, Luca ; Schühle, Udo ; Berghmans, David ; Auchère, Frédéric

published in Astronomy & Astrophysics, 656 issue id.L16 (2021)

Abstract: Brightenings observed in solar extreme-ultraviolet images are generally interpreted as signatures of micro- or nanoflares occurring in the transition region or at coronal temperatures. Recent observations with the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter have revealed the smallest of such brightenings (called campfires) in the quiet-Sun corona. Analyzing EUI 174 Å data obtained at a resolution of about 400 km on the Sun with a cadence of 5 s on 30 May 2020, we report here a number of cases in which these campfires exhibit propagating signatures along their apparently small (3-5 Mm) loop-like structures. The measured propagation speeds are generally between 25 km s−1 and 60 km s−1. If the loop plasma is assumed to be at a million Kelvin, these apparent motions would be slower than the local sound speed. Furthermore, these brightenings exhibit nontrivial propagation characteristics such as bifurcation, merging, reflection, and repeated plasma ejections. We suggest that these features are manifestations of the internal dynamics of these small-scale magnetic structures and could provide important insights into the dynamic response (∼40 s) of the loop plasma to the heating events and also into the locations of the heating events themselves.

Keyword(s): Solar Orbiter ; EUI
DOI: 10.1051/0004-6361/202142041
Links: link

The record appears in these collections:
Royal Observatory of Belgium > Solar Physics & Space Weather (SIDC)
Science Articles > Peer Reviewed Articles
Solar-Terrestrial Centre of Excellence

 Record created 2022-01-31, last modified 2022-01-31