Related papers: SN 2023axu: A Type IIP Supernova Interacted with a…

We present the discovery of the Type II supernova SN 2023ixf in M101 and follow-up photometric and spectroscopic observations, respectively, in the first month and week of its evolution. Our discovery was made within a day of estimated…

We present complete spectropolarimetric coverage of the Type II supernova (SN) 2023ixf ranging from 1 to 120 days after explosion. Polarimetry was obtained with the Kast double spectrograph on the Shane 3m telescope at Lick Observatory. As…

Core-collapse supernovae (CCSNe) may contribute a significant amount of dust in the early universe. Freshly formed coolant molecules (e.g., CO) and warm dust can be found in CCSNe as early as ~100 d after the explosion, allowing the study…

We present near-infrared spectra of late phase (>200 d) Type Ia supernovae (SNe Ia) taken at the Subaru telescope. The [Fe II] line of SN 2003hv shows a clear flat-topped feature, while that of SN 2005W show less prominent flatness. In…

We present the results of a large grid of synthetic spectra and compare them to early spectroscopic observations of SN 1993W. This supernova was discovered close to its explosion date and at a recession velocity of 5400 km/s is located in…

We present optical and infrared (IR) observations of the type IIP SN2002hh from 3 to 397 days after explosion. The optical spectroscopic (4-397d) and photometric (3-278d) data are complemented by spectroscopic (137-381d) and photometric…

We present optical photometric and spectroscopic observations of the peculiar Type Ia supernova ASASSN-20jq/SN 2020qxp. It is a low-luminosity object with a peak absolute magnitude of $M_B=-17.1\pm0.5$ mag. Despite its low luminosity, its…

We present long-term photometric and spectroscopic studies of Circumstellar Material (CSM)-Ejecta interacting supernova (SN) ASASSN-14il in the galaxy PGC 3093694. The SN reaches a peak $r$-band magnitude of $\sim$ $-20.3 \pm 0.2$ mag…

We present near-infrared (NIR) and optical observations of the Type Ic supernova (SN Ic) SN 2021krf obtained between days 13 and 259 at several ground-based telescopes. The NIR spectrum at day 68 exhibits a rising $K$-band continuum flux…

We present near-infrared (NIR) and optical observations of the highly reddened and moderately energetic Type Ib supernova (SN) 2023dbc, {\bf covering a period from} 2 to 136 days after the explosion. By comparing its color {\bf evolution},…

The luminous Type IIn Supernova (SN) 2010jl shows strong evidence for the interaction of the SN ejecta with dense circumstellar material (CSM). We present observations of SN 2010jl for $t \sim 900$ d after its earliest detection, including…

Core-collapse Supernovae (CC-SNe) descend from progenitors more massive than about 8 Msun. Because of the young age of the progenitors, the ejecta may eventually interact with the circumstellar medium (CSM) via highly energetic processes…

We present optical and near-IR data of three Type II supernovae (SNe II), SN 2008bm, SN 2009aj, and SN 2009au. These SNe display the following common characteristics: signs of early interaction of the ejecta with circumstellar material…

A longstanding problem in the study of supernovae (SNe) has been the relationship between the Type IIP and Type IIL subclasses. Whether they come from distinct progenitors or they are from similar stars with some property that smoothly…

We present extensive observations of the Type II supernova (SN II) 2023ufx which is likely the most metal-poor SN II observed to-date. It exploded in the outskirts of a low-metallicity ($Z_{\rm host} \sim 0.1~Z_\odot$) dwarf ($M_g =…

Type IIP supernova progenitors are often surrounded by dense circumstellar media that may result from mass-loss enhancement of the progenitors shortly before their explosions. Previous light-curve studies suggest that the mass-loss rates…

We present NuSTAR observations of the nearby SN 2023ixf in M101 (d=6.9 Mpc) which provide the earliest hard X-ray detection of a non-relativistic stellar explosion to date at $\delta t\approx$4-d and $\delta t\approx$11-d. The spectra are…

We present photometry and spectroscopy of the type IIP supernova 2009bw in UGC 2890 from few days after the outburst to 241 days. The light curve of SN 2009bw during the photospheric phase is similar to that of normal SNe IIP but with…

Extensive photometric and spectroscopic observations of SN1994aj until 540d after maximum light have been obtained. The photometry around maximum suggests that the SN belongs to the Type II Linear class, with a peak absolute magnitude of Mv…

SN2009ku, discovered by Pan-STARRS-1, is a Type Ia supernova (SNIa), and a member of the distinct SN2002cx-like class of SNeIa. Its light curves are similar to the prototypical SN2002cx, but are slightly broader and have a later rise to…