The Bright Optical Flash and Afterglow from the Gamma-Ray Burst GRB 130427A

Gamma-ray bursts (GRBs), bright flashes of gamma-ray light, are thought to be associated with the collapse of massive stars. GRB 130427A was detected on 27 April 2013, and it had the longest gamma-ray duration and one of the largest isotropic energy releases observed to date (see the Perspective by [Fynbo][1] ). Ackermann et al. (p. [42][2], published online 21 November) report data obtained with the Fermi Gamma-Ray Space Telescope, which reveal a high-energy spectral component that cannot be accounted for by the standard external shock synchrotron radiation model. Vestrand et al. (p. [38][3], published online 21 November) report the detection of an extremely bright flash of visible light and unexpected similarities between the variations of optical light and the highest-energy gamma rays that indicate a common origin. A detailed analysis of the first pulse of GRB 130427A by Preece et al. (p. [51][4], published online 21 November) suggests that existing models cannot explain all the observed spectral and temporal behaviors simultaneously. Maselli et al. (p. [48][5], published online 21 November) present x-ray and optical light curves of the burst's prompt emission as well as of its afterglow as recorded by the Swift satellite and a range of ground-based telescopes. [1]: /lookup/doi/10.1126/science.1248522 [2]: /lookup/doi/10.1126/science.1242353 [3]: /lookup/doi/10.1126/science.1242316 [4]: /lookup/doi/10.1126/science.1242302 [5]: /lookup/doi/10.1126/science.1242279