Tag Archives: flares

96. Evaluation of Applicability of a Flare Trigger Model
 Based on a Comparison of Geometric Structures

Contributed by Yumi Bamba. Posted on April 23, 2018

A sample of 32 flare events are analyzed to evaluate how these events agree with a flare-triggering model, which examines shear angles of large-scale magnetic field and small-scale dipole field during the flares’ precursor brightening.

90. A Comparative Study of the Eruptive and Non-Eruptive Flares Produced by the Largest Active Region of Solar Cycle 24

Contributed by Ranadeep Sarkar. Posted on March 18, 2018

AR12192, the largest active region in Solar Cycle 24, produced 6 X-class flares, but none of them were associated with a CME. However, a much weaker flare, of M4.0-class, was associated with a CME. Magnetic field and morphological changes are analyzed during these flares to understand why this is the case.

84. Abrupt and Permanent Changes of the Photospheric Magnetic Field During 75 flares observed with HMI

Contributed by Sebastián Castellanos Durán. Posted on January 16, 2018

Magnetic field changes associated with solar flares, observed by the SDO/HMI, are surveyed, and permanent changes of magnetic field are found in the majority of flare events. Properties of the magnetic field changes are further investigated.

77. Statistical Study of Solar White-light Flares and Comparison with Superflares on Solar-type Stars

Contributed by Kouske Namekata. Posted on November 30, 2017

Statistical studies find that white-light flares from the Sun and from solar-type stars have similar energy-duration relations, but the stellar flares have shorter duration. Cooling effect and stronger magnetic field in the stellar corona are proposed to explain this difference.

25. Solar Flare Forecasting Using HMI Vector Magnetic Field Data with a Support Vector Machine Algorithm

Contributed by Sebastien Couvidat. Posted on August 11, 2014

We attempt to forecast M- and X-class solar flares using a support vector machine algorithm and 4 years of HMI vector magnetic field data. With the true skill statistic as the preferred metric to estimate the algorithm performances, we obtain good predictive abilities. This may be partly due to fine-tuning the algorithm for this purpose, and to a choice of 13 SHARP parameters obtained from vector magnetograms.

9. HMI as “Coronagraph”?

Contributed by Juan-Carlos Martínez Oliveros. Posted on March 26, 2014

Reports of white-light ejecta above the limb of the Sun and imaged without the aid of a true coronagraph are exceedingly rare. Here we report the successful use of HMI to observe flare effects in the corona by the use of differencing as a substitute for an actual occulter.