Related papers: SN 2008iy circumstellar interaction: Bright and le…

Supernovae (SNe) with strong interactions with circumstellar material (CSM) are promising candidate sources of high-energy neutrinos and gamma rays, and have been suggested as an important contributor to Galactic cosmic rays beyond 1 PeV.…

We provide additional observational evidence that some Type Ia supernovae (SNe Ia) show signatures of circumstellar interaction (CSI) with hydrogen-rich material. Early phase optical and near-infrared (NIR) light curves and spectroscopy of…

We propose a model to account for the bolometric light curve, quasi-continuum and the Ca II emission features of the peculiar type Ia supernova (SN) 2002ic, which exploded in a dense circumstellar envelope. The model suggests that the SN Ia…

I analyse peculiar properties of light curve and continua of enigmatic Ibn supernovae, including SN 2006jc, and argue in favour of the early strong circumstellar interaction. This interaction explains the high luminosity and fast flux rise…

Optical spectroscopy of the Type Ia supernova SN 2002ic obtained on 2003 June 27.6 UT, i.e., about 222 rest-frame days after explosion, is presented. Strong H emission indicates an interaction between the expanding SN ejecta and an H-rich…

We report Nearby Supernova Factory observations of SN 2005gj, the second confirmed case of a "hybrid" Type Ia/IIn supernova. Our early-phase photometry of SN 2005gj shows that the interaction is much stronger than for the prototype, SN…

The near-maximum spectra of the Type Ia SN 1999ee are reviewed. Two narrow absorption features corresponding to the strongest component of the CaII IR triplet appear in the spectra from 7 days before to 2 days after B-band maximum, at a…

We present observations of the Type Ia supernova 2003du and report the detectionof an unusual, high-velocity component in the Ca II infrared triplet, similar tofeatures previously observed in SN 2000cx and SN 2001el. This feature exhibits a…

Supernovae of Type IIn (narrow line) appear to be explosions that had strong mass loss before the event, so that the optical luminosity is powered by the circumstellar interaction. If the mass loss region has an optical depth $>c/v_s$,…

Superluminous supernovae radiate up to 100 times more energy than normal supernovae. The origin of this energy and the nature of their stellar progenitors are poorly understood. We identify neutral iron lines in the spectrum of one such…

We present a new maximum-light optical spectrum of the the extremely low luminosity and exceptionally low energy Type Ia supernova (SN Ia) 2008ha, obtained one week before the earliest published spectrum. Previous observations of SN 2008ha…

We present new pre-maximum and late-time optical photometry of the Type Ia/IIn supernova 2002ic. These observations are combined with the published V-band magnitudes of Hamuy et al. (2003) and the VLT spectrophotometry of Wang et al. (2004)…

Supernovae of type Ia (SNeIa) can be produced by the explosion of slowly-rotating carbon-oxygen white dwarfs whose mass increases beyond a critical value by mass accretion. Collision with circumstellar material during their photospheric and…

I present an overview of optical observations (mostly spectra) of Type II supernovae. SNe II are defined by the presence of hydrogen, and exhibit a very wide variety of properties. SNe II-L tend to show evidence of late-time interaction…

I explore a phenomenon of the circumstellar H alpha and H beta absorption lines in the spectrum of luminous type IIL SN 2008fq taken on day 6.8 after the discovery. The absorpion is identified with the radiatively accelerated preshock wind…

We present spectroscopic and photometric observations of the Type IIn supernova (SN) 2008iy. SN 2008iy showed an unprecedentedly long rise time of ~400 days, making it the first SN to take significantly longer than 100 days to reach peak…

The effects of the interaction between Type Ia supernova ejecta and their circumstellar wind on the photometric properties of Type Ia supernovae are investigated. We assume that a hydrogen-rich, dense, and extended circumstellar matter…

We present extensive ugrizYHJK photometry and optical spectroscopy of SN 2005gj obtained by the SDSS-II and CSP Supernova Projects, which give excellent coverage during the first 150 days after the time of explosion. These data show that SN…

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…

We report the discovery of a supernova (SN) with the highest apparent energy output to date and conclude that it represents an extreme example of the Type IIn subclass. The SN, which was discovered behind the Large Magellanic Cloud at z =…