A Study of Small-Scale Brightenings using EUV Data from SPICE on board Solar Orbiter

Recently small-scale solar dynamic features have been observed on the Sun by Solar Orbiter/EUI (Berghmans et al. 2021; Panesar et al. 2021; Fludra et al. 2021). These events were initially referred to as “campfires” and “beacons”. Campfires are small-scale heating events observed mainly in the solar corona, while beacons are bright and compact structures in the quiet Sun network observed in several transition regions lines; they are identified as a transition region signature of coronal bright points. We study these events using Solar Orbiter’s Spectral Imaging of Coronal Environment (SPICE; SPICE Consortium et al. 2020). SPICE is a high-resolution imaging spectrometer that observes the Sun in Extreme Ultraviolet (EUV) wavelengths. We analyze intensity oscillations in these small-scale brightenings in the upper chromosphere and transition region using time series of Ne VIII 770 Å, CIII 977 Å, OVI 1032 Å, and Lyman-β 1026 Å observed in wide slit (30”) movies. We have performed periodogram analysis using both Fourier Transform and Lomb-Scargle methods. Our analysis confirms the oscillatory nature of small-scale brightenings, which have periods ranging between 2 and 6 min through the transition region.