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CALDER working papers have not gone through final formal review and should be cited as working papers. They are intended to encourage discussion and suggestions for revision before final publication. Any opinions, findings, and conclusions expressed in these papers are those of the authors and do not necessarily reflect the views of the Urban Institute, the(More)
We report our discovery and early observations of the peculiar Type IIn supernova SN 2006gy in NGC 1260, revealing that it reached a peak magnitude of −22, making it the most luminous supernova ever recorded. It had a very slow rise to maximum that took about 70 days and stayed brighter than −21 mag for about 100 days. It is not yet clear what powers the(More)
We derive the criteria for deflagration to detonation transition (DDT) in a Type Ia supernova. The theory is based on the two major assumptions: (i) detonation is triggered via the Zeldovich gradient mechanism inside a region of mixed fuel and products, (ii) the mixed region is produced by a turbulent mixing of fuel and products either inside an active(More)
Strong toroidal magnetic fields generated in stellar collapse can generate magneto-centrifugal jets in analogy to those found in simulations of black hole accretion. Magneto-centrifugal jets may explain why all core collapse supernovae are found to be substantially asymmetric and predominantly bi-polar. We describe two phases: the initial LeBlanc-Wilson jet(More)
We estimate the frequency of intermittent hypermutation events and disruptions of planetary/satellite photochemistry due to ultraviolet radiation from core collapse supernova explosions. Calculations are presented for planetary systems in the local Milky Way, including the important moderating effects of vertical Galactic structure and UV absorption by(More)
any individuals contributed in important ways to this report. First, we thank Rebecca Maynard, former project director and co-principal investigator, whose hard work, creative thinking, and strong leadership during the evaluation's first several years made this study and report possible. We also thank Amy Johnson, who provided critical support throughout(More)
Using observations from an extensive monitoring campaign with the Hubble Space Telescope we present the detection of an intermediate time flux excess which is redder in color relative to the afterglow of GRB 011121, currently distinguished as the gamma-ray burst with the lowest known redshift. The red " bump, " which exhibits a spectral roll-over at ∼7200Å,(More)
We report observations of SN 2004dt obtained with the Very Large Telescope of the European Southern Observatory on August 13.30, 2004 when the super-nova was more than a week before optical maximum. SN 2004dt showed strong lines of O I, Mg II, Si II, and Ca II with typical velocities of absorption minimum around 17,000 km s −1. The line profiles show(More)