Extreme-Ultraviolet Wave and Accompanying Loop Oscillations

TL;DR

This paper reports multi-instrument observations of an EUV wave from active region NOAA 12887, analyzing its wave and non-wave components, loop oscillations, and propagation characteristics relative to a CME.

Contribution

It provides detailed analysis of EUV wave components, loop oscillation periods, and magnetic field estimates, combining observations from SDO and STEREO-A.

Findings

EUV wave includes fast-mode waves, stationary fronts, and wave trains.

Loop oscillation periods range from 230 to 549 seconds.

EUV wave propagates ahead of the CME leading edge.

Abstract

We present the observations of an extreme-ultraviolet (EUV) wave, which originated from the active region (AR) NOAA 12887 on 28 October 2021 and its impact on neighbouring loops. The event was observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) satellite at various wavebands and by the Solar TErrestrial RElations Observatory-Ahead (STEREO-A) with its Extreme-Ultraviolet Imager (EUVI) and COR1 instruments with a different view angle than SDO. We show that the EUV wave event consists of several waves as well as non-wave phenomena. The wave components include: the fast-mode part of the EUV wave event, creation of oscillations in nearby loops, and the appearance of wave trains. The non-wave component consists of stationary fronts. We analyze selected oscillating loops and find that the periods of these oscillations range from 230 - 549 s. Further, we compute the density ratio inside and outside the loops and the magnetic field strength. The computed density ratio and magnetic field are found in the range of 1.08 - 2.92 and 5.75 - 8.79 G, respectively. Finally, by combining SDO and STEREO-A observations, we find that the observed EUV wave component propagates ahead of the CME leading edge.