Fire and fury heralded the birth of the solar system
doi:10.1038/nindia.2019.42 Published online 8 April 2019
Superflares coughed out by the Sun about 4.5 billion years ago, when it was still young, played a key role in the evolution of the planetary system, says a new study1. The proof comes from a short-lived, now-extinct evidence of a radioactive isotope of beryllium (7Be) buried in a meteorite fossil discovered in Kazakhstan in 1962.
"During its nascent phase, the Sun was begetting super flares with X-ray luminosity a million times stronger than the strongest X-ray flaring event of 1859,” Ritesh Kumar Mishra, corresponding author of the report, told Nature India.
The solar flares irradiate the cloud of gas and dust that rotates around the sun (or the proto-planetary disk). This cloud is a source of short-lived nuclides and of corresponding materials that make up the planets, says the report. These millimetre-sized solar system solids 'cooked’ by super flares in the proto-planetary disk "were transported over distances of a few astronomical units in a short time of about a year giving rise to the planetary system," Mishra says.
They arrived at the conclusion from the simultaneous study of radioactive decay of two beryllium isotopes – short-lived 7Be (half-life 53 days) and long-lived 10Be (half-life 1.38 million years) – in the meteorite sample. The analysis was carried out using an ion mass spectrometer at the Physical Research Laboratory, Ahmedabad.
"This has important consequences for experimental and theoretical studies in the fields of astronomy, astrophysics and planetary sciences, which significantly advance our current understanding of the formation and early evolution of the Solar system," the authors report.
1. Mishra, R. K. & Marhas, K. K. Meteoritic evidence of a late superflare as source of 7Be in the early Solar System. Nat. Astronom. (2019) doi: 10.1038/s41550-019-0716-0