Abstract Details

Name: Hema Kharayat
Affiliation: Udaipur Solar Observatory, Physical Research Laboratory
Conference ID: ASI2021_464
Title : Origin of fast coronal mass ejection and associated M-class flare from transient coronal sigmoid in active region NOAA 11909
Authors and Co-Authors : Hema Kharayat(Udaipur Solar Observatory, Physical Research Laboratory, Udaipur, 313 001, India), Bhuwan Joshi(Udaipur Solar Observatory, Physical Research Laboratory, Udaipur, 313 001, India), Prabir K. Mitra(Udaipur Solar Observatory, Physical Research Laboratory, Udaipur, 313 001, India), P. K. Manoharan(Arecibo Observatory, University of Central Florida, Puerto Rico, USA), Christian Monstein(Istituto Ricerche Solari Locarno (IRSOL), Via Patocchi 57, 6605 Locarno Monti, Switzerland)
Abstract Type : Poster
Abstract Category : Sun and the Solar System
Abstract : We present a multi-wavelength and multi-instrument analysis to investigate the formation and disruption of a coronal sigmoid from the active region (AR) NOAA 11909 on 07 December 2013. The sigmoid formation initiated ≈1 hour before its eruption, through a coupling between two twisted coronal loop systems. Due to its short life-time, this sigmoid can be regarded as ‘transient’ sigmoid. A comparison between coronal and photospheric images suggests that the coronal sigmoid was formed over a magnetically dispersed and simple β-type AR. With the observations from Helioseismic magnetic imager on board Solar Dynamics Observatory, we noticed the moving magnetic features and significant decrease in the photospheric magnetic field of the AR during the extended pre-eruption phase, which suggests the tether-cutting reconnection as a possible triggering mechanism. Successful eruption of the sigmoidal structure (flux rope) results a two- ribbon M1.2 flare and a fast halo CME (with a linear speed of ≈1085 km s-1). A typical “sigmoid-to-arcade” transformation is observed during the evolution of the flare. During the precursor phase of the flare, flux rope undergoes a slow rise (≈15 km s-1) which subsequently transitions into a fast eruption (≈110 km s-1). The two-phase evolution of the flux rope shows temporal associations with the soft X-ray precursor and impulsive phase emissions of the M-class flare, respectively, thus pointing toward a feedback relationship between magnetic reconnection and early CME dynamics. Radio observations reveal type III and type II radio bursts in meter wavelengths during the impulsive phase of the flare.