We present the discovery, photometric, and spectroscopic follow-up observations of SN 2010X (PTF 10bhp). This supernova decays exponentially with τ$_ d $ = 5 days and rivals the current recordholder in speed, SN 2002bj. SN 2010X peaks at M $_ r $ = …
We report SMARTS, Gemini, and Swift-UVOT observations of the optical transient (OT) associated with gamma-ray burst (GRB) 091127, at redshift 0.49, taken between 0.9 hr and 102 days following the Swift trigger. In our early-time observations, the OT …
We present observations and analysis of the broad-band afterglow of Swift GRB 071025. Using optical and infrared (RIYJHK) photometry, we derive a photometric redshift of 4.4 < z < 5.2; at this redshift our simultaneous multicolour observations …
Context. In August 2008, the accreting milli-second X-ray pulsar (AMXP), IGR J00291+5934, underwent an outburst lasting åisebox-0.5ex 100 days, the first since its discovery in 2004. Aims: We present data from the 2008 double-peaked outburst of IGR …
We present broadband (gamma-ray, X-ray, near-infrared, optical, and radio) observations of the Swift gamma-ray burst (GRB) 090709A and its afterglow in an effort to ascertain the origin of this high-energy transient. Previous analyses suggested that …
Supernova (SN) 2006gy was a hydrogen-rich core-collapse SN that remains one of the most luminous optical SNe ever observed. The total energy budget (>2 × 10$^51$ erg radiated in the optical alone) poses many challenges for standard SN theory. We …
We present results of an extensive observing campaign of the short- duration, hard spectrum gamma-ray burst (GRB) 070724A, aimed at detecting the radioactively powered emission that might follow from a binary merger or collapse involving compact …
We present spectroscopic and photometric observations of the Type IIn supernova (SN) 2008iy. SN 2008iy showed an unprecedentedly long rise time of åisebox-0.5ex 400 d, making it the first known SN to take significantly longer than 100 d to reach peak …
We present progenitor-star detections, light curves, and optical spectra of supernova (SN) 2009ip and the 2009 optical transient in UGC 2773 (U2773-OT), which were not genuine SNe. Precursor variability in the decade before outburst indicates that …
Long-duration gamma-ray bursts (GRBs) are widely believed to be highly collimated explosions (bipolar conical outflows with half- opening angle þeta≈ 1°-10°). As a result of this beaming factor, the true energy release from a GRB is usually several …