Related papers: Two strong white-light solar flares in AR NOAA 126…
Since the launch of the Solar Dynamics Observatory (SDO) in 2010 and throughout the solar cycle 24, the Sun has produced few tens of xclass flares, which are the most energetic solar events. Those flares are produced in regions where the…
We examine two successive flare eruptions (X5.4 and X1.3) on 2012 March 7 in the NOAA active region 11429 and investigate the magnetic field reconfiguration associated with the two eruptions. Using an advanced non-linear force-free field…
Solar flares are complex phenomena driven by the release of magnetic energy, but a large energy reservoir is not sufficient to determine their eruptive potential; the magnetic topology and plasma dynamics play a key role. We investigate the…
We investigated four major solar flare events that occurred in active regions NOAA 10930 (December 13 and 14, 2006) and NOAA 11158 (February 13 and 15, 2011) by using data observed by the Solar Optical Telescope (SOT) onboard the Hinode…
The first X-class flare of the current solar cycle 24 occurred in Active Region NOAA 11158 during its central meridian passage on 2011 February 15. This two ribbon white-light flare was well observed by the Helioseismic and Magnetic Imager…
Using the observations from the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO), we investigate six X-class and twenty-nine M-class flares occurring in solar active…
Solar flares are often associated with coronal eruptions, but there are confined ones without eruption, even for some X-class flares. How such large flares occurred and why they are confined are still not well understood. Here we studied a…
We present a multiwavelength analysis of two homologous, short lived, impulsive flares of GOES class M1.4 and M7.3, that occurred from a very localized mini-sigmoid region within the active region NOAA 12673 on 2017 September 7. Both flares…
Active region NOAA 12673 was extremely volatile in 2017 September, producing many solar flares, including the largest of solar cycle 24, an X9.3 flare of 06 September 2017. It has been reported that this flare produced a number of sunquakes…
Sunquakes are created by the hydrodynamic response of the lower atmosphere to a sudden deposition of energy and momentum. In this study we investigate a sunquake that occurred in NOAA active region 11675 on 17 February 2013. Observations of…
The impact of solar-stellar activity on planetary environments is a topic of great interest within the Sun-Earth system as well as exoplanetary systems. In particular, extreme events such as flares and coronal mass ejections have a profound…
The solar active region (AR) 12192 was one of the most flare productive region of solar cycle 24, which produced many X-class flares; the most energetic being an X3.1 flare on October 24, 2014 at 21:10 UT. Customarily, such events are…
NOAA Active Region (AR) 13664/8 produced the most intense geomagnetic effects since the ``Halloween'' event of 2003. The resulting extreme solar storm is believed to be the consequence of multiple interacting coronal mass ejections (CMEs).…
We explore the processes of repetitive build-up and explosive release of magnetic energy together with the formation of magnetic flux ropes that eventually resulted into three homologous eruptive flares of successively increasing…
On 2024 May 10/11, the strongest geomagnetic storm since November 2003 has occurred, with a peak Dst index of -412 nT. The storm was caused by NOAA Active Region (AR) 13664, which was the source of a large number of coronal mass ejections…
Forecasting solar energetic particles (SEPs), and identifying flare/CMEs from active regions (ARs) that will produce SEP events in advance is extremely challenging. We investigate the magnetic field environment of AR 12673, including the…
We have analyzed multi-wavelength observations and magnetic-field data for the solar flare of May 10, 2012 (04:18 UT) and have detected a sign inversion of the signal in the line-of-sight magnetic measurements in the umbra of a small spot.…
Solar active region (AR) 12673 produced 4 X-class, 27 M-class, and numerous lower class flares during its passage across the visible solar disk in September 2017. Our study is to answer the questions why this AR was so flare-productive and…
Photospheric magnetic field not only plays important roles in building up free energy and triggering solar eruptions, but also has been observed to change rapidly and permanently responding to the coronal magnetic field restructuring due to…
We analyze the magnetic evolution of solar active region (AR) NOAA 11476 that, between 9 and 10 May 2012, produced a series of surge-type eruptions accompanied by GOES X-ray class M flares. Using force-free models of the AR coronal…