Abstract
Active regions, which are mainly responsible for the energetic blast from the Sun so-called flare, have a highly concentrated magnetic field. Almost all flares have been attributed to the dynamics of its magnetic field on the photosphere. One method to know the changings is through studying their properties using magnetogram data. The data that are obtained from Helioseismic Magnetic Imager (HMI) instruments onboard Solar Dynamics Observatory (SDO) have a good temporal resolution which can make a better analysis. We analyze three properties of photospheric magnetic field namely total photospheric magnetic free energy (TOTPOT), total unsigned vertical current (TOTUSJZ) and total unsigned current helicity (TOTUSJH) of the active region (AR) 12740 which produced almost M-class flare at the very minimum phase of solar cycle 24. Then, we compared their values to the average values of all the corresponding parameters for almost one solar cycle. The results showed that the values of each parameter in AR 12740 was below the average values of C-flare-productive ARs. The TOTPOT was half of the average while TOTUSJH and TOTUSJZ were around one-third of the average.
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