Related papers: SN 2003bg: The First Type IIb Hypernova

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.…

We present a detailed analysis of the extremely luminous Type IIn supernova SN2006gy using spectra obtained between days 36 and 237 after explosion. We derive the temporal evolution of the effective temperature, radius, expansion speeds,…

Synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW are compared to spectra of the unusual Type Ib supernova 2005bf. We confirm the discovery by Folatelli et al. (2006) that very early spectra (about…

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…

We present ground-based and Hubble Space Telescope optical observations of the X-ray flash (XRF) 020903, covering 300 days. The afterglow showed a very rapid rise in the first day, followed by a relatively slow decay in the next few days.…

Spectral observations of the type-IIb supernova (SN) 2016gkg at 300-800 days are reported. The spectra show nebular characteristics, revealing emission from the progenitor star's metal-rich core and providing clues to the kinematics and…

We present optical and ultraviolet observations of nearby type Ic supernova SN 2017ein as well as detailed analysis of its progenitor properties from both the early-time observations and the prediscovery Hubble Space Telescope (HST) images.…

We present our observations and analysis of SN 2023gpw, a hydrogen-rich superluminous supernova (SLSN II) with broad emission lines in its post-peak spectra. Unlike previously observed SLSNe II, its light curve suggests an abrupt drop…

$UBVRI$ photometry and medium resolution optical spectroscopy of peculiar Type Ia supernova SN 2005hk are presented and analysed, covering the pre-maximum phase to around 400 days after explosion. The supernova is found to be underluminous…

We present a set of photometric and spectroscopic observations of a bright Type Ib supernova SN 2012au from -6d until ~+150d after maximum. The shape of its early R-band light curve is similar to that of an average Type Ib/c supernova. The…

We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of…

We present optical light curves of five Type Ia supernovae (2002er, 2002fk, 2003cg, 2003du, 2003fk). The photometric observations were performed in a set of intermediate-band filters. SNe 2002er, 2003du appear to be normal SN Ia events with…

We present early observations of the afterglow of the Gamma-Ray Burst (GRB) 030329 and the spectroscopic discovery of its associated supernova SN 2003dh. We obtained spectra of the afterglow of GRB 030329 each night from March 30.12 (0.6…

We present 39 nights of optical photometry, 34 nights of infrared photometry, and 4 nights of optical spectroscopy of the Type Ia SN 1999ac. This supernova was discovered two weeks before maximum light, and observations were begun shortly…

We present a comprehensive multi-epoch photometric and spectroscopic study of SN 2024bch, a nearby (19.9 Mpc) Type II supernova (SN) with prominent early high ionization emission lines. Optical spectra from 2.9 days after the estimated…

Photometric and spectroscopic observations of the peculiar Type Ib Supernova 1991D are presented. SN 1991D was exceptionally bright for a Type Ib supernova. The He I lines were rather weak and the velocity at the photosphere as a function…

We present empirical fits to the UBVRI light curves of type Ia supernovae. These fits are used to objectively evaluate light curve parameters. We find that the relative times of maximum light in the filter passbands are very similar for…

Optical and near-infrared observations of the gamma-ray burst GRB 031203, at z = 0.1055, are reported. A very faint afterglow is detected superimposed to the host galaxy in our first infrared JHK observations, carried out ~9 hours after the…

We present early-stage analyses of low-resolution ($R=1000$) optical spectra and near-infrared light curves of the bright Type II supernova (SN II) 2023ixf in the notable nearby face-on spiral galaxy M101, which were obtained from $t=1.7$…

Type IIn supernovae (SNe) resembling SN 2009ip (09ip-like SNe) originate from the interaction between circumstellar material (CSM) and the ejecta. This subclass not only shares similar observational properties around the maximum, but is…