In this study, we, for the first time, compiled all publicly available annually or biannually resolved C records, which fully covers 7 grand solar minima at an annual and bi-annual resolution. Our results from 7 grand solar minima showed a clear relationship between the rate of increase (decrease) in solar activity levels and how long the onset (termination) of the grand solar minima will last. Additionally, we show a weaker relationship between the durations of onsets and terminations and between the rate of increase and decrease of solar activity levels.
View Article and Find Full Text PDFThrough variations in its magnetic activity at different timescales, the Sun strongly influences the space weather conditions throughout the heliosphere. The most known solar activity variation is the Schwabe Cycle, also known as the Sunspot Cycle (SCs), period of which ranges from 9 to 13 years. The Sun also shows shorter quasi-periodic variations, such as the quasi-biennial oscillations (QBOs), superposed on the SCs.
View Article and Find Full Text PDFGalactic Cosmic Rays (GCRs) are charged particles, originating from galactic and/or extra-galactic Supernova Remnants (SNR), that continuously permeate the Heliosphere. The GCRs are modulated in the heliosphere by convection by solar wind (SW), drift via gradients and curvatures in the Heliospheric Magnetic Field (HMF), diffusion from fluctuations in the HMF, and adiabatic cooling in the expanding SW. An improved understanding of their modulation is imperative as studies on the variations in solar activity levels and solar eruptions in the past rely heavily on the relationship between their modulation and formation of the secondary particles in the Earth's atmosphere.
View Article and Find Full Text PDFSuperflares are large explosive events on stellar surfaces one to six orders-of-magnitude larger than the largest flares observed on the Sun throughout the space age. Due to the huge amount of energy released in these superflares, it has been speculated if the underlying mechanism is the same as for solar flares, which are caused by magnetic reconnection in the solar corona. Here, we analyse observations made with the LAMOST telescope of 5,648 solar-like stars, including 48 superflare stars.
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