Dynamics of Coronal Bright Points as seen by Sun Watcher using Active Pixel System detector and Image Processing (SWAP), Atmospheric Imaging Assembly AIA), and Helioseismic and Magnetic Imager (HMI)

摘要

The \textit{Sun Watcher using Active Pixel system detector and ImageProcessing}(SWAP) on board the \textit{PRoject for OnBoard Autonomy\todash 2}(PROBA\todash 2) spacecraft provides images of the solar corona in EUV channelcentered at 174 \AA. These data, together with \textit{Atmospheric ImagingAssembly} (AIA) and the \textit{Helioseismic and Magnetic Imager} (HMI) onboard \textit{Solar Dynamics Observatory} (SDO), are used to study the dynamicsof coronal bright points. The evolution of the magnetic polarities andassociated changes in morphology are studied using magnetograms andmulti-wavelength imaging. The morphology of the bright points seen inlow-resolution SWAP images and high-resolution AIA images show differentstructures, whereas the intensity variations with time show similar trends inboth SWAP 174 and AIA 171 channels. We observe that bright points are seen inEUV channels corresponding to a magnetic-flux of the order of $10^{18}$ Mx. Wefind that there exists a good correlation between total emission from thebright point in several UV\todash EUV channels and total unsigned photosphericmagnetic flux above certain thresholds. The bright points also show periodicbrightenings and we have attempted to find the oscillation periods in brightpoints and their connection to magnetic flux changes. The observed periods aregenerally long (10\todash 25 minutes) and there is an indication that theintensity oscillations may be generated by repeated magnetic reconnection.