The center of the Type Ia supernova remnant SNR 0509- 67.5 is empty of any ex-companion star to M_V=+8.4

• Jesper Sollerman

Room: KTH meeting room, 5th floor arXiv:1201.2195; Bradley E. Schaefer, Ashley Pagnotta

Unusual Central Engine Activity in the Double Burst GRB 110709B

• Christoffer Lundman

Room: KTH meeting room, 5th floor arXiv:1111.2922; Zhang, Bin-Bin; Burrows, David; Zhang, Bing; Meszaros, Peter; Wang, Xiang-Yu; Stratta, Giulia; D'Elia, Valerio; Frederiks, Dmitry; Golenetskii, Sergey; Cummings, Jay R.; Norris, Jay P.; Falcone, Abraham; Barthelmy, Scott D.; Gehrels, Neil

Minimum Variability Time Scales of Long and Short GRBs

• Josefin Larsson

Room: KTH meeting room, 5th floor arXiv:1201.4431; G. A. MacLachlan, A. Shenoy, E. Sonbas, K. S. Dhuga, B. Cobb, T. N. Ukwatta, D. C. Morris, A. Eskandarian, L. C. Maximon, W. C. Parke