ﻻ يوجد ملخص باللغة العربية
Low-luminosity type II supernovae (LL SNe~II) make up the low explosion energy end of core-collapse SNe, but their study and physical understanding remain limited. We present SN,2016aqf, a LL SN~II with extensive spectral and photometric coverage. We measure a $V$-band peak magnitude of $-14.58$,mag, a plateau duration of $sim$100,days, and an inferred $^{56}$Ni mass of $0.008 pm 0.002$,msun. The peak bolometric luminosity, L$_{rm bol} approx 10^{41.4}$,erg,s$^{-1}$, and its spectral evolution is typical of other SNe in the class. Using our late-time spectra, we measure the [ion{O}{i}] $lambdalambda6300, 6364$ lines, which we compare against SN II spectral synthesis models to constrain the progenitor zero-age main-sequence mass. We find this to be 12 $pm$ 3,msun. Our extensive late-time spectral coverage of the [ion{Fe}{ii}] $lambda7155$ and [ion{Ni}{ii}] $lambda7378$ lines permits a measurement of the Ni/Fe abundance ratio, a parameter sensitive to the inner progenitor structure and explosion mechanism dynamics. We measure a constant abundance ratio evolution of $0.081^{+0.009}_{-0.010}$, and argue that the best epochs to measure the ratio are at $sim$200 -- 300,days after explosion. We place this measurement in the context of a large sample of SNe II and compare against various physical, light-curve and spectral parameters, in search of trends which might allow indirect ways of constraining this ratio. We do not find correlations predicted by theoretical models; however, this may be the result of the exact choice of parameters and explosion mechanism in the models, the simplicity of them and/or primordial contamination in the measured abundance ratio.
We present early-time ($t < +50$ days) observations of SN 2019muj (= ASASSN-19tr), one of the best-observed members of the peculiar SN Iax class. Ultraviolet and optical photometric and optical and near-infrared spectroscopic follow-up started from $
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 optical spectroscopic and photometric observations of Type Ia supernova (SN) 2006X from --10 to +91 days after the $B$-band maximum. This SN exhibits one of the highest expansion velocity ever published for SNe Ia. At premaximum phases, th
A series of optical and one near-infrared nebular spectra covering the first year of the Type Ia supernova SN 2011fe are presented and modelled. The density profile that proved best for the early optical/ultraviolet spectra, rho-11fe, was extended to
In this work we present a uniform analysis of the temperature evolution and bolometric luminosity of a sample of 29 type-II supernovae (SNe), by fitting a black body model to their multi-band photometry. Our sample includes only SNe with high quality