STARS: SUPERNOVAE: GENERAL

Submillijansky Transients in Archival Radio Observations

We report the results of a 944 epoch survey for transient sources with archival data from the Very Large Array spanning 22 years with a typical epoch separation of 7 days. Observations were obtained at 5 or 8.4 GHz for a single field of view and …

Keck and European Southern Observatory Very Large Telescope View of the Symmetry of the Ejecta of the XRF/SN 2006aj

Nebular-phase spectra of SN 2006aj, discovered in coincidence with XRF 060218, were obtained with Keck in 2006 July and VLT in 2006 September. At the latter epoch spectropolarimetry was also attempted, yielding a polarization upper limit of …

When Do Internal Shocks End and External Shocks Begin? Early-Time Broadband Modeling of GRB 051111

Even with the renaissance in gamma-ray burst (GRB) research fostered by the Swift satellite, few bursts have both contemporaneous observations at long wavelengths and exquisite observations at later times across the electromagnetic spectrum. We …

Identification of the Red Supergiant Progenitor of Supernova 2005cs: Do the Progenitors of Type II-P Supernovae Have Low Mass?

The stars that end their lives as supernovae (SNe) have been directly observed in only a handful of cases, mainly because of the extreme difficulty of identifying them in images obtained prior to the SN explosions. Here we report the identification …

The Unique Type Ib Supernova 2005bf: A WN Star Explosion Model for Peculiar Light Curves and Spectra

Observations and modeling for the light curve (LC) and spectra of supernova (SN) 2005bf are reported. This SN showed unique features: the LC had two maxima, and declined rapidly after the second maximum, while the spectra showed strengthening He …

Discovery of a Transient U-Band Dropout in a Lyman Break Survey: A Tidally Disrupted Star at z=3.3?

We report the discovery of a transient source in the central regions of galaxy cluster A267. The object, which we call ``PALS-1,`` was found in a survey aimed at identifying highly magnified Lyman break galaxies in the fields of intervening rich …

The Supernova Associated with GRB 031203: SMARTS Optical-Infrared Light Curves from 0.2 to 92 Days

Optical and infrared monitoring of the afterglow site of gamma-ray burst GRB 031203 has revealed a brightening source embedded in the host galaxy, which we attribute to the presence of a supernova (SN) related to the GRB (``SN 2003lw''). We present …

The Detailed Optical Light Curve of GRB 030329

We present densely sampled BVRI light curves of the optical transient associated with the gamma-ray burst (GRB) 030329, the result of a coordinated observing campaign conducted at five observatories. Augmented with published observations of this GRB, …

Photometry and Spectroscopy of GRB 030329 and Its Associated Supernova 2003dh: The First Two Months

We present extensive optical and infrared photometry of the afterglow of gamma-ray burst (GRB) 030329 and its associated supernova (SN) 2003dh over the first two months after detection (2003 March 30-May 29 UT). Optical spectroscopy from a variety of …

Toward an Understanding of the Progenitors of Gamma-Ray Bursts

The various possibilities for the progenitors of gamma-ray bursts (GRBs) manifest in differing observable properties. Through deep spectroscopic and high-resolution imaging observations of some GRB hosts, I demonstrate that well-localized …