2024-12-13 マックス・プランク研究所
Artist’s impression of a superflaring sun-like star as seen in visible light. © MPS/Alexey Chizhik
＜関連情報＞
- https://www.mpg.de/23854476/solar-superflares-once-per-century
- https://www.science.org/doi/10.1126/science.adl5441
太陽のような恒星は、およそ1世紀に1度スーパーフレアを発生させる Sun-like stars produce superflares roughly once per century
Valeriy Vasilyev, Timo Reinhold, Alexander I. Shapiro, Ilya Usoskin, […], and Laurent Gizon
Science Published:12 Dec 2024
DOI:https://doi.org/10.1126/science.adl5441
Editor’s summary
Solar flares are bright, transient, multiwavelength emissions from active regions on the Sun. The most intense directly observed solar flares release energies of about 1032 erg. It is unclear whether the Sun can produce more intense flares than that or how often they might occur. Vasilyev et al. investigated brightness measurements of 56,000 Sun-like stars observed by the Kepler space telescope. They identified almost 3000 bright stellar flares with energies of about 1034 to 1035 erg, which are called superflares. The occurrence rate is about one superflare per star per century. If the Sun behaves like the stars in this sample, then it could produce superflares at a similar rate. —Keith T. Smith
Abstract
Stellar superflares are energetic outbursts of electromagnetic radiation that are similar to solar flares but release more energy, up to 1036 erg on main-sequence stars. It is unknown whether the Sun can generate superflares and, if so, how often they might occur. We used photometry from the Kepler space observatory to investigate superflares on other stars with Sun-like fundamental parameters. We identified 2889 superflares on 2527 Sun-like stars, out of 56,450 observed. This detection rate indicates that superflares with energies >1034 erg occur roughly once per century on stars with Sun-like temperature and variability. The resulting stellar superflare frequency-energy distribution is consistent with an extrapolation of the Sun’s flare distribution to higher energies, so we suggest that both are generated by the same physical mechanism.
