In the realm of energy and space science, a team of researchers from Arizona State University, including Steven J. Desch, Ashley K. Herbst, Richard L. Hervig, and Benjamin Jacobsen, has been delving into the mysteries of our early solar system. Their recent study, published in the Astrophysical Journal, aims to constrain the flux of solar energetic particles (SEPs) in the Sun’s protoplanetary disk, a crucial factor for understanding the early solar system’s environment.
The researchers focused on the emissions from solar flares, which release X-rays and high-energy ions known as SEPs. Astronomical observations have shown that the solar mass-protostellar fluxes were significantly higher in the past, ranging from 300 to 3000 times greater than the present-day Sun. Understanding these fluxes is vital for modeling various processes in the protoplanetary disk, such as ionization, magnetorotational instability, magnetocentrifugal outflows, and even the production of short-lived radionuclides.
Previous interpretations of meteoritic data had suggested extraordinarily high flux values, up to 6 million times the present-day Sun. However, the team re-examined these data and presented a more nuanced picture. They found that cosmogenic neon in hibonite grains was likely produced as these grains resided in the disk. Additionally, they concluded that chlorine-36 was created in chlorine-poor grains after the disk had dissipated, and beryllium-10 was primarily inherited from the molecular cloud, with minimal production in the disk. Furthermore, there was no evidence to support the presence of live beryllium-7 in calcium-aluminum-rich inclusions (CAIs).
The researchers demonstrated that these findings are consistent with a flux value of approximately 3000 times the present-day Sun for the first 5 million years of the solar nebula. This suggests that the early Sun emitted a flux of X-rays and SEPs that was not atypical for a protostar. This research provides a more accurate understanding of the early solar system’s environment, which is crucial for energy and space science, particularly in the context of solar energy and space weather prediction.
The study, titled “The Extent of Solar Energetic Particle Irradiation in the Sun’s Protoplanetary Disk,” was published in the Astrophysical Journal, offering valuable insights into the early solar system’s environment and its implications for the energy sector.
This article is based on research available at arXiv.