Abstract Details
| Name: VASANTHARAJU N Affiliation: Bangalore University, Bengaluru Conference ID: ASI2019_48 Title : Temporal evolution of magnetic field parameters leading to the largest flare (X9.3) of Solar cycle 24 Authors and Co-Authors : N.Vasantharaju, B.Ravindra, P.Vemareddy and V.H.Doddamani Abstract Type : Poster Abstract Category : Sun and the Solar System Abstract : Solar Active region(AR) NOAA 12673 produced 4 X-class, 27 M-class and 45 C-class flares during its solar disk passage from 29 August 2017 to 10 September 2017. It produced two consecutive major flares, X2.2 at 8:57 UT and X9.3 at 11:53 UT on 6 September 2017. The X2.2 flare remained confined and helped in the build up of magnetic flux rope system, which eventually erupted during X9.3 flare as a Halo CME. The X2.2 flare likely weakened the magnetic topology facilitating the eruptive X9.3 flare. We used SHARP series of vector magnetogram data of Helioseismic and Magnetic Imager (HMI) on board Solar Dynamics Observatory (SDO) as the boundary condition to estimate the background field by potential field approximation. Our initial results of the temporal evolution of background field confirms the above said scenario. Also, we studied the temporal evolution of different magnetic field parameters like Total Magnetic flux, Degree of Net-vertical-current neutralisation (NVCN), average alpha and Magnetic free-energy during the AR transformation from simple α-configuration (2 September 2017) to complex βγδ-configuration (7 September 2017) and found that the AR has the fast emerging flux rate, presence of strong non-neutralised currents and highly sheared configuration leads to build up of magnetic free-energy favours the conditions for strong eruptivity of AR. In my talk, results related to the evolution of non-potentiality of AR leading to strong flares will be presented. |