Sep 6 – 10, 2021
Online
Europe/Rome timezone

Extreme UV quiet Sun brightenings observed by Solar Orbiter/EUI

Sep 6, 2021, 12:03 PM
13m
Online

Online

Poster Session 2 - The Solar Atmosphere: Heating, Dynamics and Coupling Poster Session 1.2

Speaker

David Berghmans (Royal Observatory of Belgium)

Description

We present results of the first high cadence image sequence of the Extreme Ultraviolet Imager (EUI) taken on 2020 May 30, when Solar Orbiter was 31.5 degrees in solar longitude separated from Earth & SDO, and at 0.56AU from the Sun. At this distance, the two-pixel spatial resolution of EUI’s High Resolution EUV Telescope (HRIEUV) was 400 km. HRIEUV observed a quiet Sun region and detected small localised brightenings, nicknamed ’campfires’, with length scales between 400 km and 4000 km and durations between 10 sec and 200 sec. The smallest and weakest of these HRIEUV brightenings have not been previously observed. Simultaneous observations from the EUI High-resolution Lyman-α telescope (HRILYA) do not show localised brightening events, but the locations of the HRIEUV events clearly correspond to the chromospheric network. Comparisons with simultaneous AIA images shows that most events can also be identified in the 17.1 nm, 19.3 nm, 21.1 nm, and 30.4 nm pass-bands of AIA, although they appear weaker and blurred. Our differential emission measure (DEM) analysis indicated coronal temperatures. We determined the height for a few of these campfires to be between 1 and 5 Mm above the photosphere. We interpret these events as a new extension to the flare-microflare-nanoflare family. Given their low height, the EUI ‘campfires’ could stand as a new element of the fine structure of the transition region-low corona, that is, as apexes of small-scale loops that undergo internal heating all the way up to coronal temperatures.

Primary author

David Berghmans (Royal Observatory of Belgium)

Co-authors

Frédéric Auchère (Université Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale, 91405 Orsay, France) Dr David M. Long (Mullard Space Science Laboratory, University College London, UK) Elie Soubrié (Institut d’Astrophysique Spatiale) Dr Marilena MIerla (Royal Observatory of Belgium) Dr Andrei Zhukov (Royal Observatory of Belgium) U. Schühle (Max Planck Intitute for Solar System Research) Dr Patrick Antolin (Northumbria University) Louise Harra (PMOD/WRC and ETH-Zurich) Susanna Parenti (Institut d'Astrophysique Spatiale, CNRS/Université Paris-Saclay) Dr Elena Podladchikova R. Aznar Cuadrado (Max Planck Institute for Solar System Research) Dr Eric Buchlin (Universit ́e Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale, 91405, Orsay, France) Dr Laurent Dolla (Royal Observatory of Belgium) Cis Verbeeck (Royal Observatory of Belgium) Samuel Gissot L Teriaca (Max Planck Institute for Solar System Research) Margit Haberreiter Thanassis Katsiyannis (Royal Observatory of Belgium) Luciano Rodriguez (Royal Observatory of Belgium) Emil Kraaikamp (Royal Observatory of Belgium) Philip Smith (Mullard Space Science Laboratory, University College London, UK) Koen Stegen Pierre Rochus (Centre Spatial de Liège) Jean-Philippe Halain (Centre Spatial de Liège) Lionel Jacques (Centre Spatial de Liège) William Thompson (NASA GSFC) Dr Bernd Inhester (Max-Plank Institute for Solar System Research)

Presentation materials