ﻻ يوجد ملخص باللغة العربية
We present optical spectroscopy together with ultraviolet, optical and near-infrared photometry of SN 2019hcc, which resides in a host galaxy at redshift 0.044, displaying a sub-solar metallicity. The supernova spectrum near peak epoch shows a `w shape at around 4000 {AA} which is usually associated with O II lines and is typical of Type I superluminous supernovae. SN 2019hcc post-peak spectra show a well-developed H alpha P-Cygni profile from 19 days past maximum and its light curve, in terms of its absolute peak luminosity and evolution, resembles that of a fast-declining Hydrogen-rich supernova (SN IIL). The object does not show any unambiguous sign of interaction as there is no evidence of narrow lines in the spectra or undulations in the light curve. Our tardis spectral modelling of the first spectrum shows that Carbon, Nitrogen and Oxygen (CNO) at 19000 K reproduce the `w shape and suggests that a combination of non-thermally excited CNO and metal lines at 8000 K could reproduce the feature seen at 4000 {AA}. The Bolometric light curve modelling reveals that SN 2019hcc could be fit with a magnetar model, showing a relatively strong magnetic field (B > 3 x 10^14 G), which matches the peak luminosity and rise time without powering up the light curve to superluminous luminosities. The high-energy photons produced by the magnetar would then be responsible for the detected O II lines. As a consequence, SN 2019hcc shows that a `w shape profile at around 4000 {AA}, usually attributed to O II, is not only shown in superluminous supernovae and hence it should not be treated as the sole evidence of the belonging to such a supernova type.
We present the photometry and spectroscopy of SN 2015an, a Type II Supernova (SN) in IC 2367. The recombination phase of the SN lasts up to $sim$120 d, with a decline rate of 1.24 mag/100d, higher than the typical SNe IIP. The SN exhibits bluer colou
We present high-cadence, comprehensive data on the nearby ($Dsimeq33,rm{Mpc}$) Type II SN 2017ahn, discovered within $sim$1 day of explosion, from the very early phases after explosion to the nebular phase. The observables of SN 2017ahn show a signif
We present high-cadence ultraviolet (UV), optical, and near-infrared (NIR) data on the luminous Type II-P supernova SN 2017gmr from hours after discovery through the first 180 days. SN 2017gmr does not show signs of narrow, high-ionization emission l
We present $81$ near-infrared (NIR) spectra of $30$ Type II supernovae (SNe II) from the Carnegie Supernova Project-II (CSP-II), the largest such dataset published to date. We identify a number of NIR features and characterize their evolution over ti
We present our analysis of the Type II supernova DLT16am (SN~2016ija). The object was discovered during the ongoing $rm{D}<40,rm{Mpc}$ (DLT40) one day cadence supernova search at $rsim20.1,rm{mag}$ in the `edge-on nearby ($D=20.0pm1.9,rm{Mpc}$) galax