Search Publications
Study of solar activities associated with a Halo CME on 17 Feb 2023 event
Ahamed, A. Ansar; Subramanian, S. Prasanna; Rahman, A. Mujiber +3 more
In the present work, propagation of an earth directed fast and wide Coronal Mass Ejection event on 17 February 2023 is studied in detail. The complex magnetic configuration in the Active Region (AR) 13229 at N25E64 caused an intensive X2.3 flare with a peak at 19:38 UT. It is followed by a massive halo CME event observed in the LASCO C3 coronagrap…
Relations between global seismic parameters and activity cycles of the Sun
Chang, Heon-Young; Kim, Ki-Beom
It is suggested that the dependency of the global asteroseismic parameters on stellar properties such as magnetic activity is carefully calibrated with a homogenous data sample in stellar parameters in the sense that the empirical scaling relations of the global asteroseismic parameters are used in estimating fundamental stellar properties. As an …
An association of CMEs with solar flares detected by Fermi γ-ray burst monitor during solar cycle 24
Abdel-Sattar, Walid; Mawad, Ramy; Farid, Hussein M.
By performing certain spatial and temporal criteria, we obtained 492 CME events simultaneously associated with GBM solar flare events (hereafter, GBM-flare-CME) from the total number 5123 Gamma-ray Burst Monitor (GBM) solar flares and 15228 Coronal Mass Ejections (CMEs) detected during the solar cycle 24 (2008-2019). Among these 492 events, which …
A new approximate coupling function: The case of Forbush decreases
Xaplanteris, L.; Livada, M.; Mavromichalaki, H. +1 more
We attempt the derivation of a new coupling function between ground level and primary cosmic rays for the case of Forbush decreases. The calculations for the new function are based on basic Quantum Field Theory theoretical tools, something that has not been attempted till now in other widely used cosmic ray coupling functions. The use of Quantum F…
Enhancing coronal structures with radial local multi-scale filter
Ji, Kaifan; Bai, Xianyong; Liu, Hui +2 more
Images of the corona contain information over a wide range of spatial scales and various structures such as coronal holes, coronal loops, coronal mass ejections (CMEs), and helmet streamers with differences in brightness. Therefore, processing these images is important for determining various types of information. However, it is very difficult to …
The characteristics of the coronal mass ejections preceding the associated X-ray and γ-ray burst solar flares
Abdel-Sattar, Walid; Mawad, Ramy
In this study, investigated 14,786 coronal mass ejection (CME) events and 5092 Gamma-ray Burst Monitor (GBM) solar flare events (called γ-ray burst solar flare) recorded during 2008-2017, by using temporal and spatial conditions criteria, we found 845 (about 16%) CME events associated with γ-ray burst solar flare events only (hereafter, CME-γ-pref…
Detection of coronal mass ejections using AdaBoost on grayscale statistic features
Guo, Juan; Zhang, Ling; Yin, Jian-qin +2 more
We present an automatic algorithm to detect coronal mass ejections (CMEs) in Large Angle Spectrometric Coronagraph (LASCO) C2 running difference images. The algorithm includes 3 steps: (1) split the running difference images into blocks according to slice size and analyze the grayscale statistics of the blocks from a set of images with and without…
On some properties of coronal mass ejections in solar cycle 23
Mittal, Nishant; Narain, Udit
We have investigated some properties such as speed, apparent width, acceleration, latitude, mass and kinetic energy, etc. of all types of coronal mass ejections (CMEs) observed during the period 1996-2007 by SOHO/LASCO covering the solar cycle 23. The results are in satisfactory agreement with previous investigations.
Changes in the photospheric magnetic field associated with solar flares
Lin, Jun; Mei, Zhixing
The flare-related, persistent and abrupt changes in the photospheric magnetic field have been reported by many authors during recent years. These bewildering observational results pose a challenge to the current flare theories in which the photospheric magnetic field usually remains unchanged in the eruption. In this paper, changes in the photosph…
Evolution of morphological features of CMEs deduced from catastrophe model of solar eruptions
Lin, J.; Soon, W.
We describe the evolution of morphological features of the magnetic configuration of CME according to the catastrophe model developed previously. For the parameters chosen for the present work, roughly half of the total mass is nominally contained in the initial flux rope, while the remaining plasma is brought by magnetic reconnection from the cor…