An extremely luminous X-ray outburst at the birth of a supernova

• Published in: Nature Vol. 453; no. 7194; pp. 469 - 474
• Main Authors: Soderberg, A. M, Berger, E, Page, K. L, Schady, P, Parrent, J, Pooley, D, Wang, X.-Y, Ofek, E. O, Cucchiara, A, Rau, A, Waxman, E, Simon, J. D, Bock, D. C.-J, Milne, P. A, Page, M. J, Barentine, J. C, Barthelmy, S. D, Beardmore, A. P, Bietenholz, M. F, Brown, P, Burrows, A, Burrows, D. N, Byrngelson, G, Cenko, S. B, Chandra, P, Cummings, J. R, Fox, D. B, Gal-Yam, A, Gehrels, N, Immler, S, Kasliwal, M, Kong, A. K. H, Krimm, H. A, Kulkarni, S. R, Maccarone, T. J, Mészáros, P, Nakar, E, O'Brien, P. T, Overzier, R. A, de Pasquale, M, Racusin, J, Rea, N, York, D. G
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.05.2008; Nature Publishing; Nature Publishing Group
• Subjects: Astronomy; Astrophysics; Earth, ocean, space; Exact sciences and technology; Explosions; Humanities and Social Sciences; Late stages of stellar evolution (including black holes); multidisciplinary; Observations; Science; Science (multidisciplinary); Shock waves; Stars; Stars & galaxies; Supernovae; X-rays; United States; Collapse; Galaxy evolution; Shock waves; Supernovae explosion; Supernovae; Neutrinos; Elementary particles; Cosmic x-ray bursts; Massless particles; X ray emission; Massive stars
• ISSN: 0028-0836; 1476-4687; 1476-4679
• DOI: 10.1038/nature06997

Massive stars end their short lives in spectacular explosions—supernovae—that synthesize new elements and drive galaxy evolution. Historically, supernovae were discovered mainly through their ‘delayed’ optical light (some days after the burst of neutrinos that marks the actual event), preventing observations in the first moments following the explosion. As a result, the progenitors of some supernovae and the events leading up to their violent demise remain intensely debated. Here we report the serendipitous discovery of a supernova at the time of the explosion, marked by an extremely luminous X-ray outburst. We attribute the outburst to the ‘break-out’ of the supernova shock wave from the progenitor star, and show that the inferred rate of such events agrees with that of all core-collapse supernovae. We predict that future wide-field X-ray surveys will catch each year hundreds of supernovae in the act of exploding. Birth of a supernova: X rays mark the spot On 9 January 2008, a routine viewing of the galaxy NGC 2770 with the Swift observatory's X-ray telescope struck lucky. An unexpected transient X-ray burst, lasting 3 minutes 40 seconds, was detected in one of the galaxy's spiral arms. Further observations have shown this to have been a first sighting of a new type Ibc supernova, duly named SN2008D. Previously, supernovae of this type, the results of spectacular explosions of short-lived but massive stars, have been discovered mainly as delayed optical light hours after the actual event. But this X-ray burst originated just moments after the explosion, probably representing the 'break-out' of the supernova shock wave from the progenitor star. Its prompt discovery makes SN2008D one of the best-studied normal supernovae to date. And there are important implications for future work, since wide-field X-ray satellite observations should be able to uncover hundreds of new supernovae per year close to the time of explosion. Supernovae are usually discovered through their 'delayed' light, which becomes visible some hours after the actual event. Now Soderberg et al . report the discovery of a supernova at the time of the explosion, marked by an extremely luminous X-ray outburst.