We present extensive ground-based and $Hubble~Space~Telescope$ ($HST$) photometry of the highly reddened, very nearby type Ia supernova (SN Ia) 2014J in M82, covering the phases from 9 days before to about 900 days after the $B$-band maximum. SN 2014J is similar to other normal SNe Ia near the maximum light, but it shows flux excess in the $B$ band in the early nebular phase. This excess flux emission can be due to light scattering by some structures of circumstellar materials located at a few 10$^{17}$ cm, consistent with a single degenerate progenitor system or a double degenerate progenitor system with mass outflows in the final evolution or magnetically driven winds around the binary system. At t$\sim$+300 to $\sim$+500 days past the $B$-band maximum, the light curve of SN 2014J shows a faster decline relative to the $^{56}$Ni decay. Such a feature can be attributed to the significant weakening of the emission features around [Fe III] $λ$4700 and [Fe II] $λ$5200 rather than the positron escape as previously suggested. Analysis of the $HST$ images taken at t$>$600 days confirms that the luminosity of SN 2014J maintains a flat evolution at the very late phase. Fitting the late-time pseudo-bolometric light curve with radioactive decay of $^{56}$Ni, $^{57}$Ni and $^{55}$Fe isotopes, we obtain the mass ratio $^{57}$Ni/$^{56}$Ni as $0.035 \pm 0.011$, which is consistent with the corresponding value predicted from the 2D and 3D delayed-detonation models. Combined with early-time analysis, we propose that delayed-detonation through single degenerate scenario is most likely favored for SN 2014J.
We use the results of a supernova light-curve population synthesis to predict the range of possible supernova light curves arising from a population of single-star progenitors that lead to type IIP supernovae. We calculate multiple models varying the initial mass, explosion energy, nickel mass and nickel mixing and then compare these to type IIP supernovae with detailed light curve data and pre-explosion imaging progenitor constraints. Where a good fit is obtained to observations, we are able to achieve initial progenitor and nickel mass estimates from the supernova lightcurve that are compara…
Aims. We present and analyse late-time observations of the type-Ib supernova with possible pre-supernova progenitor detection, iPTF13bvn, taken at $\sim$300 days after the explosion, and discuss these in the context of constraints on the supernova's progenitor. Previous studies have proposed two possible natures for the progenitor of the supernova, i.e. a massive Wolf-Rayet star or a lower-mass star in close binary system. Methods. Our observations show that the supernova has entered the nebular phase, with the spectrum dominated by Mg~I]$λλ$4571, [O~I]$λλ$6300, 6364, and [Ca~II]$λλ$7291, 7324…
In this study we include axions in stellar evolution models adopting the current stringest constraints for their coupling to photons and electrons. We obtain that the minimum stellar mass of Core Collapse Supernova (CCSN) progenitors is shifted up by nearly 2 Mo. This result seems to be in tension with the observationaly derived minimum mass of CCSN progenitors.
The explosion outcome and diagnostics of core-collapse supernovae depend sensitively on the nature of the stellar progenitor, but most studies to date have focused exclusively on one-dimensional, spherically-symmetric massive star progenitors. We present some of the first core-collapse supernovae simulations of three-dimensional massive star supernovae progenitors, a 12.5- and a 15-M$_{\odot}$ model, evolved in three-dimensions from collapse to bounce through explosion with the radiation-hydrodynamic code F{\sc{ornax}}. We compare the results using those starting from three-dimensional progeni…
Although Type Ia supernovae have been heavily scrutinized due to their use in making cosmological distance estimates, we are still unable to definitively identify the progenitors for the entire population. While answers have been presented for certain specific systems, a complete solution remains elusive. We present observations of two supernova remnants (SNRs) in the Large Magellanic Cloud, SNR 0505-67.9 and SNR 0509-68.7, for which we have identified the center of the remnant and the 99.73% containment central region in which any companion star left over after the supernova must be located. …
We review all the models proposed for the progenitor systems of Type Ia supernovae and discuss the strengths and weaknesses of each scenario when confronted with observations. We show that all scenarios encounter at least a few serious diffculties, if taken to represent a comprehensive model for the progenitors of all Type Ia supernovae (SNe Ia). Consequently, we tentatively conclude that there is probably more than one channel leading SNe Ia. While the single-degenerate scenario (in which a single white dwarf accretes mass from a normal stellar companion) has been studied in some detail, the …
Type IIb supernovae are believed to originate from core-collapse progenitors having kept only a very thin hydrogen envelope. We aim to explore how some physical factors, such as rotation, metallicity, overshooting, and the initial orbital period in binaries, significantly affect the Roche lobe overflow and the formation of type IIb supernovae. It is found that binaries are the main channel that capable of producing type typeIIb supernovae progenitors in the mass range for initial masses below 20 $M_{\odot}$. The formation of type IIb supernova progenitors is extremely sensitive to the initial …
We report and discuss post-explosion observations of supernova iPTF13bvn. We find that the brightness of the SN at +740 days is below the level of the pre-explosion source and thus confirm that the progenitor star has gone. We estimate that the late-time brightness is still dominated by the supernova, which constrains the magnitude and thus mass of a possible companion star to below approximately 10Msun. In turn this implies that the progenitor's initial mass is constrained to a narrow range of between 10 to 12Msun. The progenitor of iPTF13bvn would have been a helium giant rather than a Wolf-…
We present Large Binocular Telescope difference imaging data for the final years of four Type II-P/L supernovae progenitors. For all four, we find no significant evidence for stochastic or steady variability in the U, B, V, or R-bands. Our limits constrain variability to no more than roughly 5-10% of the expected R-band luminosities of the progenitors. These limits are comparable to the observed variability of red supergiants in the Magellanic Clouds. Based on these four events, the probability of a Type II-P/L progenitor having an extended outburst after Oxygen ignition is <37% at 90% confide…
Connecting observations of core-collapse supernova explosions to the properties of their massive star progenitors is a long-sought, and challenging, goal of supernova science. Recently, Barker et al. (2022) presented bolometric light curves for a landscape of progenitors from spherically symmetric neutrino-driven core-collapse supernova (CCSN) simulations using an effective model. They find a tight relationship between the plateau luminosity of the Type II-P CCSN light curve and the terminal iron core mass of the progenitor. Remarkably, this allows us to constrain progenitor properties with ph…
Stars in the mass range from 8 to 10 solar masses are expected to produce one of two types of supernovae (SNe), either electron-capture supernovae (ECSNe) or core-collapse supernovae (CCSNe), depending on their previous evolution. Either of the associated progenitors retain extended and massive hydrogen-rich envelopes, the observables of these SNe are, therefore, expected to be similar. In this study we explore the differences in these two types of SNe. Specifically, we investigate three different progenitor models: a solar-metallicity ECSN progenitor with an initial mass of 8.8 solar masses, …
We present results of a systematic study of the mass-loss properties of Type IIn supernova progenitors within decades before their explosion. We apply an analytic light curve model to 11 Type IIn supernova bolometric light curves to derive the circumstellar medium properties. We reconstruct the mass-loss histories based on the estimated circumstellar medium properties. The estimated mass-loss rates are mostly higher than 1e-3 Msun/yr and they are consistent with those obtained by other methods. The mass-loss rates are often found to be constantly high within decades before their explosion. Thi…
The dominant radioactive energy source powering Type Ia supernova light curves is expected to switch from the decay of $^{56}$Co to $^{57}$Co at very late epochs. We use archival HST images of SN1992A obtained more than 900 days after explosion to constrain its cobalt isotopic abundance ratio and compare it to the well-studied event SN2011fe. We confirm the $^{57}$Co / $^{56}$Co ratio for SN2011fe of $0.026\pm 0.004$ found by arXiv:1608.01155, consistent with a "double degenerate" progenitor scenario. For SN1992A, we find a ratio of $0.034\pm 0.010$, but the large uncertainty does not allow us…
Core-collapse supernovae showing little or no hydrogen (denoted by Type IIb and Ib, respectively) are the explosions of massive stars that have lost some or most of their outer envelopes. How they lose their mass is unclear, but it likely involves binary interaction. So far, seven progenitors of such supernovae have been identified in pre-explosion imaging (five for Type IIb events and two for Type Ib events). Here, we evolve detailed binary stellar evolution models in order to better understand the nature of these progenitors. We find that the amount of hydrogen left in the envelope at the ti…
Red supergiants have been confirmed as the progenitor stars of the majority of hydrogen-rich type II supernovae. However, while such stars are observed with masses >25M$_\odot$, detections of >18M$_\odot$ progenitors remain elusive. Red supergiants are also expected to form at all metallicities, but discoveries of explosions from low-metallicity progenitors are scarce. Here, we report observations of the type II supernova, SN 2015bs, for which we infer a progenitor metallicity of $\leq$0.1Z$_\odot$ from comparison to photospheric-phase spectral models, and a Zero Age Main-Sequence mass of 17-2…
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 are enhanced up to ~ 0.1 Msun/yr, assuming a constant wind velocity. However, density of circumstellar media at the immediate stellar vicinity can be much higher than previously inferred for a given mass-loss rate if wind acceleration is taken into account. We show that the wind acceleration has a huge impact when we estimate mass-loss rates from early light c…
The progenitors of many Type II supernovae have been observationally identified but the search for Type Ibc supernova (SN Ibc) progenitors has thus far been unsuccessful, despite the expectation that they are luminous Wolf-Rayet (WR) stars. We investigate how the evolution of massive helium stars affects their visual appearances, and discuss the implications for the detectability of SN Ibc progenitors. Massive WR stars that rapidly lose their helium envelopes through stellar-wind mass-loss end their lives when their effective temperatures -- related to their hydrostatic surfaces -- exceed abou…
Thermonuclear (type Ia) supernovae are bright stellar explosions with the unique property that the light curves can be standardized, allowing them to be used as distance indicators for cosmological studies. Many fundamental questions bout these events remain, however. We provide a critique of our present understanding of these and present results of simulations assuming the single-degenerate progenitor model consisting of a white dwarf that has gained mass from a stellar companion. We present results from full three-dimensional simulations of convection with weak reactions comprising the A=23 …
The availability of updated model atmospheres for red supergiants and improvements in single and binary stellar evolution models, as well as previously unpublished data prompted us to revisit the progenitor of low-luminosity type II-Plateau supernova, SN 2008bk. Using mid-IR data in combination with dust models, we find that high temperature (4250-4500 K), high extinction (E(B-V)>0.7) solutions are incompatible with the data. We therefore favour a cool (~3500-3700 K) progenitor with a luminosity of log(L/Lsun)~4.53. Comparing with evolutionary tracks, we infer progenitor masses in the 8-10 Msu…
The progenitors of Type IIP supernovae (SNe) are known to be red supergiants, but their properties are not well determined. We employ hydrodynamical modelling to investigate the explosion characteristics of eight Type IIP supernovae, and the properties of their progenitor stars. We create evolutionary models using the {\sc MESA} stellar evolution code, explode these models, and simulate the optical lightcurves using the {\sc STELLA} code. We fit the optical lightcurves, Fe II 5169Å velocity, and photospheric velocity, to the observational data. Recent research has suggested that the progenitor…
We explore a new scenario for producing stripped-envelope supernova progenitors. In our scenario, the stripped-envelope supernova is the second supernova of the binary, in which the envelope of the secondary was removed during its red supergiant phase by the impact of the first supernova. Through 2D hydrodynamical simulations, we find that $\sim$50-90$\%$ of the envelope can be unbound as long as the pre-supernova orbital separation is $\lesssim5$ times the stellar radius. Recombination energy plays a significant role in the unbinding, especially for relatively high mass systems ($\gtrsim18M_\…
Type Ibn supernovae (SNe) are a rare class of stellar explosions whose progenitor systems are not yet well determined. We present and analyze observations of the Type Ibn SN 2019kbj, and model its light curve in order to constrain its progenitor and explosion parameters. SN 2019kbj shows roughly constant temperature during the first month after peak, indicating a power source (likely circumstellar material interaction) that keeps the continuum emission hot at ~15,000K. Indeed, we find that the radioactive decay of Ni56 is disfavored as the sole power source of the bolometric light curve. A rad…
The creation of "hybrid" white dwarfs, made of a C-O core within a O-Ne shell has been proposed, and studies indicate that ignition in the C-rich central region makes these viable progenitors for thermonuclear (type Ia) supernovae. Recent work found that the C-O core is mixed with the surrounding O-Ne as the white dwarf cools prior to accretion, which results in lower central C fractions in the massive progenitor than previously assumed. To further investigate the efficacy of hybrid white dwarfs as progenitors of thermonuclear supernovae, we performed simulations of thermonuclear supernovae fr…
Despite the significance of Type Ia supernovae (SNeIa) in many fields in astrophysics, SNeIa lack a theoretical explanation. The standard scenarios involve thermonuclear explosions of carbon/oxygen white dwarfs approaching the Chandrasekhar mass; either by accretion from a companion or by a merger of two white dwarfs. We investigate the contribution from both channels to the SNIa rate with the binary population synthesis (BPS) code SeBa in order to constrain binary processes such as the mass retention efficiency of WD accretion and common envelope evolution. We determine the theoretical rates …
Type Ib/c supernovae (SNe Ib/c) mark the deaths of hydrogen-deficient massive stars. The evolutionary scenarios for SNe Ib/c progenitors involve many important physical processes including mass loss by winds and its metallicity dependence, stellar rotation, and binary interactions. This makes SNe Ib/c an excellent test bed for stellar evolution theory. We review the main results of evolutionary models for SN Ib/c progenitors available in the literature and their confrontation with recent observations. We argue that the nature of SN Ib/c progenitors can be significantly different for single and…
Type II supernova progenitors are expected to emit copious amounts of mass in a dense stellar wind prior to the explosion. When the progenitor is a member of a binary, the orbital motion modulates the density of this wind. When the progenitor explodes, the high-velocity ejecta collides with the modulated wind, which in turn produces a modulated radio signal. In this work we derive general analytic relations between the parameters of the radio signal modulations and binary parameter in the limit of large member mass ratio. We use these relations to infer the semi major axis of SN1979c and a low…
Natures of progenitors of type Ia Supernovae (SNe Ia) have not yet been clarified. There has been long and intensive discussion on whether the so-called single degenerate (SD) scenario or the double degenerate (DD) scenario, or anything else, could explain a major population of SNe Ia, but the conclusion has not yet been reached. With rapidly increasing observational data and new theoretical ideas, the field of studying the SN Ia progenitors has been quickly developing, and various new insights have been obtained in recent years. This article aims at providing a summary of the current situatio…
We investigate the evolution of Type Ib/c supernova (SN Ib/c) progenitors in close binary systems, using new evolutionary models that include the effects of rotation, with initial masses of 12 - 25 Msun for the primary components, and of single helium stars with initial masses of 2.8 - 20 Msun. We find that, despite the impact of tidal interaction on the rotation of primary stars, the amount of angular momentum retained in the core at the presupernova stage in different binary model sequences converge to a value similar to those found in previous single star models. This amount is large enough…
Several recently discovered peculiar type Ia supernovae seem to demand an altogether new formation theory that might help explain the puzzling dissimilarities between them and the standard type Ia supernovae. The most striking aspect of the observational analysis is the necessity of invoking super-Chandrasekhar white dwarfs having masses ~ 2.1-2.8M_sun, M_sun being the mass of Sun, as their most probable progenitors. Strongly magnetized white dwarfs having super-Chandrasekhar masses were already established to be potential candidates for the progenitors of peculiar type Ia supernovae. Owing to…
Type Ia supernovae have proven vital to our understanding of cosmology, both as standard candles and for their role in galactic chemical evolution; however, their origin remains uncertain. The canonical accretion model implies a hot and luminous progenitor which would ionize the surrounding gas out to a radius of $\sim$10--100 parsecs for $\sim$100,000 years after the explosion. Here we report stringent upper limits on the temperature and luminosity of the progenitor of Tycho's supernova (SN 1572), determined using the remnant itself as a probe of its environment. Hot, luminous progenitors tha…
We searched through roughly 12 years of archival survey data acquired by the Katzman Automatic Imaging Telescope (KAIT) as part of the Lick Observatory Supernova Search (LOSS) in order to detect or place limits on possible progenitor outbursts of Type IIn supernovae (SNe~IIn). The KAIT database contains multiple pre-SN images for 5 SNe~IIn (plus one ambiguous case of a SN IIn/imposter) within 50 Mpc. No progenitor outbursts are found using the false discovery rate (FDR) statistical method in any of our targets. Instead, we derive limiting magnitudes (LMs) at the locations of the SNe. These lim…
The progenitor and explosion properties of type II supernovae (SNe II) are fundamental to understand the evolution of massive stars. Special interest has been given to the range of initial masses of their progenitors, but despite the efforts made, it is still uncertain. Direct imaging of progenitors in pre-explosion images point out an upper initial mass cutoff of $\sim$18$M_{\odot}$. However, this is in tension with previous studies in which progenitor masses inferred by light curve modelling tend to favour high-mass solutions. Moreover, it has been argued that light curve modelling alone can…
Supernova (SN) iPTF13bvn in NGC 5806 was the first Type Ib SN to have been tentatively associated with a progenitor candidate in pre-explosion images. We performed deep ultraviolet (UV) and optical Hubble Space Telescope (HST) observations of the SN site 740 days after explosion. We detect an object in the optical bands that is fainter than the pre-explosion object. This dimming is likely not produced by dust absorption in the ejecta; thus, our finding confirms the connection of the progenitor candidate with the SN. The object in our data is likely dominated by the fading SN, which implies tha…
Using Modules for Experiments in Stellar Astrophysics (MESA)+STELLA, we show that very different physical models can adequately reproduce a specific observed Type II-Plateau Supernova (SN). We consider SN2004A, SN2004et, SN2009ib, SN2017eaw, and SN2017gmr, Nickel-rich ($M_\mathrm{Ni}>0.03M_\odot$) events with bolometric lightcurves and a well-sampled decline from the plateau. These events also have constraints on the progenitor radius, via a progenitor image, or, in the case of SN2017gmr, a radius from fitting shock-cooling models. In general, many explosions spanning the parameter space of pr…
In this work, we study the synthetic explosions of a massive star. We take a 100 M$_{\odot}$ zero--age main--sequence (ZAMS) star and evolve it until the onset of core-collapse using {\tt MESA}. Then, the resulting star model is exploded using the publicly available stellar explosion code, {\tt STELLA}. The outputs of {\tt STELLA} calculations provide us the bolometric light curve and photospheric velocity evolution along with other physical properties of the underlying supernova. In this paper, the effects of having large Hydrogen-envelope on the supernova light curve have been explored. We a…
We present a detection in pre-explosion Hubble Space Telescope (HST) imaging of a point source consistent with being the progenitor star of the Type IIb supernova (SN IIb) 2016gkg. Post-explosion imaging from the Keck Adaptive Optics system was used to perform relative astrometry between the Keck and HST imaging. We identify a single point source in the HST images coincident with the SN position to 0.89-sigma. The HST photometry is consistent with the progenitor star being an A0Ia star with T=9500 K and log (L/Lsun)=5.15. We find that the SN 2016gkg progenitor star appears more consistent with…
We constrained the progenitor masses for 169 supernova remnants, 8 historically observed supernovae, and the black hole formation candidate in NGC 6946, finding that they are consistent with originating from a standard initial mass function. Additionally, there were 16 remnants that showed no sign of nearby star formation consistent with a core-collapse supernova, making them good Type Ia candidates. Using $Hubble$ $Space$ $Telescope$ broadband imaging, we measured stellar photometry of ACS/WFC fields in F435W, F555W, F606W, and F814W filters as well as WFC3/UVIS fields in F438W, F606W, and F8…
Over the last 15 years, the supernova community has endeavoured to identify progenitor stars of core-collapse supernovae in high resolution archival images of their galaxies.This review compiles results (from 1999 - 2013) in a distance limited sample and discusses the implications. The vast majority of the detections of progenitor stars are of type II-P, II-L or IIb with one type Ib progenitor system detected and many more upper limits for progenitors of Ibc supernovae (14). The data for these 45 supernovae progenitors illustrate a remarkable deficit of high luminosity stars above an apparent …
We show the preliminary results of our search for the progenitor systems of type Ia supernovae (SNe Ia). We model binary populations our aim being to compare these models with the observations of detailed element abundances of the hot Intra-Cluster Medium.
I summarize what we have learned about the nature of stars that ultimately explode as core-collapse supernovae from the examination of images taken prior to the explosion. By registering pre-supernova and post-supernova images, usually taken at high resolution using either space-based optical detectors, or ground-based infrared detectors equipped with laser guide star adaptive optics systems, nearly three dozen core-collapse supernovae have now had the properties of their progenitor stars either directly measured or (more commonly) constrained by establishing upper limits on their luminosities…
In a canonical model, the progenitors of Type Ia supernovae (SNe Ia) are accreting, nuclear-burning white dwarfs (NBWDs), which explode when the white dwarf reaches the Chandrasekhar mass, M_C. Such massive NBWDs are hot (kT ~100 eV), luminous (L ~ 10^{38} erg/s), and are potentially observable as luminous supersoft X-ray sources (SSSs). During the past several years, surveys for soft X-ray sources in external galaxies have been conducted. This paper shows that the results falsify the hypothesis that a large fraction of progenitors are NBWDs which are presently observable as SSSs. The data als…
We identify a pre-explosion counterpart to the nearby Type IIP supernova ASASSN-16fq (SN 2016cok) in archival Hubble Space Telescope (HST) data. The source appears to be a blend of several stars that prevents obtaining accurate photometry. However, with reasonable assumptions about the stellar temperature and extinction, the progenitor almost certainly had an initial mass M<17Msun, and was most likely in the mass range 8-12Msun. Observations once ASASSN-16fq has faded will have no difficulty accurately determining the properties of the progenitor. In 8 years of Large Binocular Telescope (LBT) …
The Mn to Cr mass ratio in supernova ejecta has recently been proposed as a tracer of Type Ia SN progenitor metallicity. We review the advantages and problems of this observable quantity, and discuss them in the framework of the Tycho Supernova Remnant. The fluxes of the Mn and Cr Kalpha lines in the X-ray spectra of Tycho observed by the Suzaku satellite suggests a progenitor of supersolar metallicity.
A precise knowledge of the masses of supernova progenitors is essential to answer various questions of modern astrophysics, such as those related to the dynamical and chemical evolution of Galaxies. In this paper we revise the upper bound for the mass of the progenitors of CO white dwarfs (\mup) and the lower bound for the mass of the progenitors of normal type II supernovae (\mups). In particular, we present new stellar models with mass between 7 and 10 \msun, discussing their final destiny and the impact of recent improvements in our understanding of the low energy rate of the \c12c12 reacti…
We present gravitational wave emission predictions based on three core collapse supernova simulations corresponding to three different progenitor masses. The masses span a large range, between 9.6 and 25 Solar masses, are all initially non-rotating, and are of two metallicities: zero and Solar. We compute both the temporal evolution of the gravitational wave strains for both the plus and the cross polarizations, as well as their spectral decomposition and characteristic strains.
We present an analysis of Chandra observations of the position of ten nearby (< 25 Mpc) type Ia supernovae, taken before the explosions. No sources corresponding to progenitors were found in any of the observations. We calculated upper limits on the bolometric luminosities of the progenitors assuming black-body X-ray spectra with temperatures of 30-150 eV. This is inspired by the fact that luminous super-soft X-ray sources have been suggested as the direct progenitors of type Ia supernovae. The upper limits of two supernovae in our sample are comparable to the luminosities of the brightest obs…
Little is observationally known about the progenitors of Type Ibc supernovae (SNe) or the typical activity of SNe progenitors in their final years. Here, we analyze deep Large Binocular Telescope imaging data spanning the 4 years before and after the Type Ic SN 2012fh using difference imaging. We place 1$σ$ upper limits on the detection of the progenitor star at $M_R>-4.0$, $M_V>-3.8$, $M_B>-3.1$, and $M_U>-3.8$ mag. These limits are the tightest placed on a Type Ic SNe and they largely rule out single star evolutionary models in favor of a binary channel as the origin of this SN. We also cons…
I present progenitor luminosities ($L$) for a sample of 112 Type II supernovae (SNe II), computed directly from progenitor photometry and the bolometric correction technique, or indirectly from empirical correlations between progenitor luminosity and [OI] $λλ$6300, 6364 line luminosity at 350 d since explosion, $^{56}$Ni mass, or absolute $V$-band magnitude at 50 d since explosion. To calibrate these correlations, I use twelve SNe II with progenitor luminosities measured from progenitor photometry. I find that the correlations mentioned above are strong and statistically significant, and allow…
SN 2007bi is an extremely luminous Type Ic supernova. This supernova is thought to be evolved from a very massive star, and two possibilities have been proposed for the explosion mechanism. One possibility is a pair-instability supernova with an M_{CO} ~ 100 M_sun CO core progenitor. Another possibility is a core-collapse supernova with M_{CO} ~ 40 M_sun. We investigate the evolution of very massive stars with main-sequence mass M_{MS} = 100 - 500 M_sun and Z_0 = 0.004, which is in the metallicity range of the host galaxy of SN 2007bi, to constrain the progenitor of SN 2007bi. The supernova ty…
We present a model for the Galactic supernova remnant (SNR) VRO 42.05.01, suggesting that its intriguing morphology can be explained by a progenitor model of a supersonically moving, mass losing star. The mass outflows of the progenitor star were in the form of an asymmetric stellar wind focused on the equatorial plane of the star. The systemic motion of the parent star in combination with its asymmetric outflows excavated an extended wind bubble that revealed a similar structure to this of VRO 42.05.01. Currently the SNR is interacting with the wind bubble and it is dominantly shaped by it. E…
We present pre-explosion photometry of the likely progenitor star of the Type II supernova (SN II) 2017eaw in NGC 6946. We use a Hubble Space Telescope (HST) image of SN 2017eaw to perform relative astrometry with HST and Spitzer Space Telescope (Spitzer) imaging, finding a single point source consistent with its position. We detect the progenitor star in $>$40 epochs of HST and Spitzer imaging covering 12.9 years to 43 days before discovery. While the progenitor luminosity was roughly constant for most of this period, there was a $\sim$20% increase in its $4.5~μ$m luminosity over the final 3 …
In order to explore various aspects of stellar evolution, supernovae, gamma ray bursts and nucleosynthesis, we have developed a new efficient stellar evolution code. In this paper we describe this new code and compare the results with the ones calculated by the previous code. Specifically we focus on the progenitor evolution of lower end of the Fe-core collapse supernovae, and mass distribution of remnant neutron stars. We describe how different assumptions will lead different neutron star mass distribution. We also review recent works of our research group.
We use the star formation history map of the Large Magellanic Cloud recently published by Harris & Zaritsky to study the sites of the youngest Type Ia supernova remnants. We find that most Type Ia remnants are associated with old, metal-poor stellar populations, with little or no recent star formation. These include SNR 0509-67.5 which is known to have been originated by an extremely bright SN 1991T-like event, and yet is located very far away from any star forming regions. The Type Ia remnant SNR N103B, however, is associated with vigorous star formation activity in the last 100 Myr, and migh…
We investigate the red supergiant problem: the apparent dearth of Type IIP supernova progenitors with masses between 16 and 30 M_sun. Although red supergiants with masses in this range have been observed, none have been identified as progenitors in pre-explosion images. We show that by failing to take into account the additional extinction resulting from the dust produced in the red supergiant winds, we risk underestimating the luminosity of the most massive red supergiants at the end of their lives. We estimate the initial masses of all Type IIP progenitors for which observations exist and an…
Supernova Ia are bright explosive events that can be used to estimate cosmological distances, allowing us to study the expansion of the Universe. They are understood to result from a thermonuclear detonation in a white dwarf that formed from the exhausted core of a star more massive than the Sun. However, the possible progenitor channels leading to an explosion are a long-standing debate, limiting the precision and accuracy of supernova Ia as distance indicators. Here we present HD265435, a binary system with an orbital period of less than a hundred minutes, consisting of a white dwarf and a h…
