We present the results of a machine-learning (ML)-based search for new R Coronae Borealis (RCB) stars and DY Persei-like stars (DYPers) in the Galaxy using cataloged light curves from the All-Sky Automated Survey (ASAS) Catalog of Variable Stars …
We present observations and interpretation of the Type IIn supernova SN 2008am discovered by the ROTSE Supernova Verification Project (RSVP). SN 2008am peaked at approximately -22.3 mag at a redshift of z = 0.2338, giving it a peak luminosity of …
We present early-time photometric and spectroscopic observations of supernova (SN) 2009kr in NGC 1832. We find that its properties to date support its classification as Type II-linear (SN II-L), a relatively rare subclass of core-collapse supernovae …
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 …
Owing to its extremely high luminosity and long duration, supernova (SN) 2006gy radiated more energy in visual light than any other known SN. Two hypotheses to explain its high luminosity at early times—that it was powered by shock interaction with …
We report the discovery and early observations of the peculiar Type IIn supernova (SN) 2006gy in NGC 1260. With a peak visual magnitude of about -22, it is the most luminous supernova ever recorded. Its very slow rise to maximum took åisebox-0.5ex 70 …
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 …