7 papers
Solar Cycle Variation of Sustained Gamma Ray Emission from the Sun
Nat Gopalswamy, Pertti Mäkelä, Seiji Yashiro +3
We investigated the occurrence rate of the sustained gamma ray emission (SGRE) events from the Sun using data obtained by Fermi Large Area Telescope (LAT) since its launch in 2008.…
Unusual Circumstances of the 2024 June 8 GLE
Nat Gopalswamy, Pertti Makela, Hong Xie +3
Ground Level Enhancement (GLE) in large solar energetic particle (SEP) events is indicative of protons accelerated to GeV energies. Almost all GLE events are associated with sustai…
Solar Cycle Variation of Sustained Gamma-ray Emission Events from the Sun and Related Energetic Events
N. Gopalswamy, P. Mäkela, S. Akiyama +2
The sustained gamma ray emission (SGRE) from the Sun is one of the fascinating high energy phenomena closely related to the acceleration of protons to energies >300 MeV. Here we re…
Multispacecraft Observations of the 2024 September 9 Backside Solar Eruption that Resulted in a Sustained Gamma Ray Emission Event
Nat Gopalswamy, Pertti Mäkelä, Sachiko Akiyama +6
We report on the 2024 September 9 sustained gamma ray emission (SGRE) event observed by the Large Area Telescope (LAT) onboard the Fermi satellite. The event was associated with a…
Third Harmonic Structure in an Interplanetary Type II Radio Burst and Other Energetic Phenomena During the 2024 September 14 Solar Eruption
Nat Gopalswamy, Pertti Makela, Hong Xie +2
We report on the observation of first, second, and third harmonic components during an interplanetary (IP) type II solar radio burst observed on 2024 September 14 by the radio inst…
The Longest Duration SGRE Event in Solar Cycle 25
Nat Gopalswamy, Pertti Makela, Hong Xie +2
Solar Cycle (SC) 24 was the weakest in the space age, yet it produced many sustained gamma ray emission (SGRE) events from the Sun. Solar cycle (SC) 25, which is a bit stronger tha…