Two-spacecraft detection of short-period decayless kink oscillations of solar coronal loops

Abstract

ABSTRACT Decayless kink oscillations of an ensemble of loops are captured simultaneously by the High Resolution Imager (HRI) of the Extreme Ultraviolet Imager (EUI) and the Atmospheric Imaging Assembly (AIA) from 22:58 ut on 2021 November 5 to 00:27 ut on 2021 November 6. Oscillations are analysed by processing image sequences taken by the two instruments with a motion magnification technique. The analysed loops are around 51 Mm in length, and oscillate with short periods of 1–3 min (1.6 min in average) and displacement amplitudes of 24–83 km. The signals recorded by AIA are delayed by 66 s as compared to HRI, which coincides with the light traveltime difference from the Sun to each instrument. After correction of this time difference, the cross-correlation coefficient between the signals from the two data varies from 0.82 to 0.97, indicating that they are well consistent. This work confirms that HRI sees the same oscillations as AIA, which is the necessary first step before proceeding to the detection of shorter time-scales by EUI. In addition, our results indicate the robustness of the dejittering procedure in the study of kink oscillations with HRI.