Related papers: The Transitional Stripped-Envelope SN 2008ax: Spec…

We present the UV, optical, X-ray, and radio properties of the Type IIb SN 2008ax discovered in NGC 4490. The observations in the UV are one of the earliest of a Type IIb supernova (SN). On approximately day four after the explosion, a…

We present spectroscopy and photometry of the He-rich supernova (SN) 2008ax. The early-time spectra show prominent P-Cygni H lines, which decrease with time and disappear completely about two months after the explosion. In the same period…

We present optical spectroscopy and spectropolarimetry of the Type IIb SN 2008aq 16 days and 27 days post-explosion. The spectrum of SN 2008aq remained dominated by Halpha P Cygni profile at both epochs, but showed a significant increase in…

Spectropolarimetry of the Type Ib SN 2008D, associated with the XRF 080109, at two separate epochs, are presented. The epochs of these observations correspond to V-band light curve maximum and 15 days after light curve maximum (or 21 and 36…

Extensive optical and near-infrared (NIR) observations of the type IIb supernova 2008ax are presented, covering the first year after the explosion. The light curve is mostly similar in shape to that of the prototypical type IIb SN 1993J,…

The early-time optical spectrum of the Type Ic supernova (SN) 2002ap was characterized by unusually broad features, leading some authors to designate it a "hypernova." We present optical spectropolarimetry of this object 16 and 37 days…

We present photometry, spectra, and spectropolarimetry of supernova (SN) 2012ab, mostly obtained over the course of $\sim 300$ days after discovery. SN 2012ab was a Type IIn (SN IIn) event discovered near the nucleus of spiral galaxy…

We present an optical spectropolarimetric observation of the unique Type Ib supernova (SN) 2005bf at 8 days after the second maximum. The data, combined with the polarization spectrum taken at 6 days before the second maximum (Maund et al.…

HET optical spectroscopy and unfiltered ROTSE-III photometry spanning the first 11 months since explosion of the Type II-P SN 2006bp are presented. Flux limits from the days before discovery combined with the initial rapid brightening…

We present optical spectroscopic and photometric observations of supernova (SN) 2008D, associated with the luminous X-ray transient 080109, at >300 days after the explosion (nebular phases). We also give flux measurements of emission lines…

The dominant mechanism and time scales over which stripped-envelope supernovae (SNe) progenitor stars shed their hydrogen envelopes are uncertain. Observations of Type Ib and Ic SNe at late phases could reveal the optical signatures of…

SN 2008D was discovered while following up an unusually bright X-ray transient in the nearby spiral galaxy NGC 2770. We present early optical spectra (obtained 1.75 days after the X-ray transient) which allowed the first identification of…

The nebular spectra of the energetic Type Ic supernova SN1998bw (hypernova) are studied. The transition to the nebular phase occurred at an epoch of about 100 days after outburst, which is assumed to coincide with GRB980425. Early in the…

The X-ray flash 080109, associated with SN 2008D, can be attributed to the shock breakout emission from a normal Type Ib/c supernova. If the observed emission is interpreted as blackbody emission, the temperature and radiated energy are…

We present photometry, spectra, and spectropolarimetry of supernova (SN) 2014ab, obtained through $\sim 200$ days after peak brightness. SN 2014ab was a luminous Type IIn SN ($M_V < -19.14$ mag) discovered after peak brightness near the…

We present six epochs of optical spectropolarimetry of the Type II supernova (SN) 2023ixf ranging from $\sim$ 2 to 15 days after the explosion. Polarimetry was obtained with the Kast double spectrograph on the Shane 3 m telescope at Lick…

We present an analysis of the optical and near-infrared properties of SN 2022lxg, a bright ($\rm M_{g\, \mathrm{peak}}=-19.41$ mag) and rapidly evolving SN. It was discovered within a day of explosion, and rose to peak brightness in 10 d.…

We present extensive early photometric (ultraviolet through near-infrared) and spectroscopic (optical and near-infrared) data on supernova (SN) 2008D as well as X-ray data analysis on the associated Swift/X-ray transient (XRT) 080109. Our…

The Type II-Plateau supernova (SN II-P) SN 2004dj was the first SN II-P for which spectropolarimetry data were obtained with fine temporal sampling before, during, and after the fall off of the photometric plateau -- the point that marks…

SN 2024aecx is a nearby ($\sim$11 Mpc) Type IIb SN discovered within $\sim$1 d after explosion. In this paper we report high-cadence photometric (typically 0.5$\sim$1 day) and spectroscopic follow-up observations, conducted from as early as…