SN 1987a: A Progress Report

1987 ◽  
Vol 7 (2) ◽  
pp. 141-146 ◽  
Author(s):  
M. A. Dopita ◽  
N. Achilleos ◽  
J. A. Dawe ◽  
C. Flynn ◽  
S. J. Meatheringham ◽  
...  
Keyword(s):  
Light Curve ◽  
Thermal Energy ◽  
Radioactive Decay ◽  
Progress Report ◽  
Type Ii ◽  
Normal Type ◽  
Spectral Evolution ◽  
Core Mass ◽  
Sn 1987A ◽  
Residual Hydrogen

AbstractIt now appears almost certain that the precursor of SN 1987a was the brighter of the components of Sk-69 202, a blue supergiant, with a precursor mass of perhaps 12-16 solar masses. Prior to the explosion the precursor had a core mass of order six solar masses, and 0.1 to 0.2 solar masses of residual hydrogen envelope. The compact nature of this star can account for many of the odd features of the subsequent light curve and spectral evolution.An analysis of the light curve and colour evolution shows four distinct epochs, which probably relate to the initial expansion of the fireball and the escape of shock-deposited thermal energy, the hydrogen-rich layers becoming optically thin, the exposure of the helium core, and the increasing transparency of the helium core.The supernova appeared to be at its maximum on May 10, but is dimmer than a normal Type II because its light is apparently derived from recombinations and the radioactive decay of 56Ni to 56Co to 56Fe rather than by the thermal energy deposited by the passage of the shock.

scholarly journals Supernovae from blue supergiant progenitors: What a mess!

2019 ◽  
Vol 622 ◽  
pp. A70 ◽  
Author(s):  
Luc Dessart ◽  
D. John Hillier
Keyword(s):  
Light Curve ◽  
Line Width ◽  
Spectroscopic Properties ◽  
Blue Color ◽  
Type Ii ◽  
Spectral Evolution ◽  
Sn 1987A ◽  
Rich Diversity ◽  
Alternative Power ◽  
Low Metallicity

Supernova (SN) 1987A was classified as a peculiar Type II SN because of its long rising light curve and the persistent presence of H I lines in optical spectra. It was subsequently realized that its progenitor was a blue supergiant (BSG), rather than a red supergiant (RSG) as for normal, Type II-P, SNe. Since then, the number of Type II-pec SNe has grown, revealing a rich diversity in photometric and spectroscopic properties. In this study, using a single 15 M⊙ low-metallicity progenitor that dies as a BSG, we have generated explosions with a range of energies and 56Ni masses. We then performed the radiative transfer modeling with CMFGEN, from 1 d until 300 d after explosion for all ejecta. Our models yield light curves that rise to optical maximum in about 100 d, with a similar brightening rate, and with a peak absolute V-band magnitude spanning −14 to −16.5 mag. All models follow a similar color evolution, entering the recombination phase within a few days of explosion, and reddening further until the nebular phase. Their spectral evolution is analogous, mostly differing in line width. With this model set, we study the Type II-pec SNe 1987A, 2000cb, 2006V, 2006au, 2009E, and 2009mw. The photometric and spectroscopic diversity of observed SNe II-pec suggests that there is no prototype for this class. All these SNe brighten to maximum faster than our limited set of models, except perhaps SN 2009mw. The spectral evolution of SN 1987A conflicts with other observations in this set and conflicts with model predictions from 20 d until maximum: Hα narrows and weakens while Ba II lines strengthen faster than expected, which we interpret as signatures of clumping. SN 2000cb rises to maximum in only 20 d and shows weak Ba II lines. Its spectral evolution (color, line width and strength) is well matched by an energetic ejecta but the light curve may require strong asymmetry. The persistent blue color, narrow lines, and weak Hα absorption, seen in SN 2006V conflicts with expectations for a BSG explosion powered by 56Ni and may require an alternative power source. In contrast with theoretical expectations, observed spectra reveal a diverse behavior for lines like Ba II 6142 Å, Na I D, and Hα. In addition to diversity arising from different BSG progenitors, we surmise that their ejecta are asymmetric, clumped, and, in some cases, not solely powered by 56Ni decay.

scholarly journals Progenitors and Hydrodynamics of Type II and lb Supernovae

1996 ◽  
Vol 145 ◽  
pp. 137-147
Author(s):  
S. E. Woosley ◽  
T. A. Weaver ◽  
R. G. Eastman
Keyword(s):  
Black Holes ◽  
Light Curve ◽  
Mass Loss ◽  
Massive Stars ◽  
The Other ◽  
Shock Interaction ◽  
Type Ii ◽  
Residual Hydrogen ◽  
Ordinary Type ◽  
The One

We review critical physics affecting the observational characteristics of those supernovae that occur in massive stars. Particular emphasis is given to 1) how mass loss, either to a binary companion or by a radiatively driven wind, affects the type and light curve of the supernova, and 2) the interaction of the outgoing supernova shock with regions of increasing pr3 in the stellar mantle. One conclusion is that Type II-L supernovae may occur in mass exchanging binaries very similar to the one that produced SN 1993J, but with slightly larger initial separations and residual hydrogen envelopes (∼1 Mʘ and radius ∼ several AU). The shock interaction, on the other hand, has important implications for the formation of black holes in explosions that are, near peak light, observationally indistinguishable from ordinary Type II-p and lb supernovae.

scholarly journals The Type II supernovae 2006V and 2006au: two SN 1987A-like events

2011 ◽  
Vol 7 (S279) ◽  
pp. 403-404
Author(s):  
Francesco Taddia
Keyword(s):  
Light Curve ◽  
Near Infrared ◽  
Light Curves ◽  
Type Ii ◽  
Host Galaxies ◽  
Remarkable Similarity ◽  
Sn 1987A ◽  
Nir Light ◽  
Initial Dip ◽  
Analytic Models

AbstractWe studied optical and near-infrared (NIR) light curves, and optical spectra of Supernovae (SNe) 2006V and 2006au, two objects monitored by the Carnegie Supernova Project (CSP) and displaying remarkable similarity to SN 1987A, although they were brighter, bluer and with higher expansion velocities. SN 2006au also shows an initial dip in the light curve, which we have interpreted as the cooling tail of the shock break-out. By fitting semi-analytic models to the UVOIR light curve of each object, we derive the physical properties of the progenitors and we conclude that SNe 2006V and 2006au were most likely Blue Supergiant (BSG) stars that exploded with larger energies as compared to that of SN 1987A. We are currently investigating the host galaxies of a few BSG SNe, in order to understand the role played by the metallicity in the production of these rare exploding BSG stars.

SN 1987A: the Light Curve

1991 ◽  
Vol 9 (1) ◽  
pp. 105-106 ◽  
Author(s):  
Patricia Whitelock ◽  
John Menzies ◽  
John A. R. Caldwell
Keyword(s):  
Light Curve ◽  
Radioactive Decay ◽  
Radioactive Isotopes ◽  
Core Collapse ◽  
Additional Contribution ◽  
Decay Energy ◽  
Sn 1987A ◽  
Total Luminosity ◽  
Light Echoes ◽  
Γ Ray

AbstractThe changing total luminosity of SN 1987A between 2 and 1200 days after core collapse is illustrated and discussed. From about four weeks after outburst the supernova light curve was dominated by the release of radioactive decay energy; the major contributor being 0.078M⊙ of 56Co. Recently an additional contribution probably from the decay of 57Co and 44Ti appears to be manifesting itself in the light curve. A gradually increasing fraction of the radioactive decay energy has probably been emitted at X- and γ-ray wavelengths; the fluxes are low and no recent measurements have been published. Most of the remaining radioactive decay energy appears to be emitted in the IR and is very difficult to measure. Other factors influencing the interpretation of the recent light curve are the uncertain contribution from long-lived radioactive isotopes and light-echoes. It is therefore premature to make any definitive statements on the contribution from the neutron star, although it is probably less than a few times 1037 erg s−1.

Ultraviolet Observations of SN 1987A

1988 ◽  
Vol 7 (4) ◽  
pp. 390-396
Author(s):  
N. Panagia
Keyword(s):  
Massive Star ◽  
Initial Configuration ◽  
Core Collapse ◽  
Type Ii ◽  
Normal Type ◽  
Sn 1987A ◽  
Photometric Observations ◽  
Ultraviolet Observations

AbstractThe IUE observations of SN 1987A are presented and the most important results are briefly summarised. The photometric observations of SN 1987A are discussed in some detail in the context of the supernova energetics. Adding the information from spectroscopy and neutrino observations, it is concluded that SN 1987A is a ‘normal’ Type II explosion (i.e. core collapse of a massive star) with an unusually compact initial configuration, just as expected for the progenitor Sk −69°202.

scholarly journals DES16C3cje: A low-luminosity, long-lived supernova

2020 ◽  
Vol 496 (1) ◽  
pp. 95-110
Author(s):  
C P Gutiérrez ◽  
M Sullivan ◽  
L Martinez ◽  
M C Bersten ◽  
C Inserra ◽  
...  
Keyword(s):  
Light Curve ◽  
Radioactive Decay ◽  
Explosion Energy ◽  
Late Time ◽  
Type Ii ◽  
Additional Energy ◽  
Dark Energy Survey ◽  
Energy Survey ◽  
Initial Peak ◽  
Absolute Brightness

ABSTRACT We present DES16C3cje, a low-luminosity, long-lived type II supernova (SN II) at redshift 0.0618, detected by the Dark Energy Survey (DES). DES16C3cje is a unique SN. The spectra are characterized by extremely narrow photospheric lines corresponding to very low expansion velocities of ≲1500 km s−1, and the light curve shows an initial peak that fades after 50 d before slowly rebrightening over a further 100 d to reach an absolute brightness of Mr ∼ −15.5 mag. The decline rate of the late-time light curve is then slower than that expected from the powering by radioactive decay of 56Co, but is comparable to that expected from accretion power. Comparing the bolometric light curve with hydrodynamical models, we find that DES16C3cje can be explained by either (i) a low explosion energy (0.11 foe) and relatively large 56Ni production of 0.075 M⊙ from an ∼15 M⊙ red supergiant progenitor typical of other SNe II, or (ii) a relatively compact ∼40 M⊙ star, explosion energy of 1 foe, and 0.08 M⊙ of 56Ni. Both scenarios require additional energy input to explain the late-time light curve, which is consistent with fallback accretion at a rate of ∼0.5 × 10−8 M⊙ s−1.

scholarly journals The difficulty of inferring progenitor masses from type-II-Plateau supernova light curves

2019 ◽  
Vol 625 ◽  
pp. A9 ◽  
Author(s):  
Luc Dessart ◽  
D. John Hillier
Keyword(s):  
Light Curve ◽  
Mass Loss ◽  
Main Sequence ◽  
Spectral Characteristics ◽  
Late Time ◽  
Type Ii ◽  
Phase Duration ◽  
Core Mass ◽  
Surface Mass ◽  
Curve Modeling

Much controversy surrounds the inferred progenitor masses of type-II-Plateau (II-P) supernovae (SNe). The debate is nourished by the discrepant results from radiation-hydrodynamics simulations, pre-explosion imaging, and studies of host stellar populations. Here, we present a controlled experiment using four solar-metallicity models with zero-age main sequence masses of 12, 15, 20, and 25 M⊙. Because of the effects of core burning and surface mass loss, these models reach core collapse as red-supergiant (RSG) stars with a similar H-rich envelope mass of 8 to 9 M⊙ but with final masses in the range 11 to 16 M⊙. We explode the progenitors using a thermal bomb, adjusting the energy deposition to yield an asymptotic ejecta kinetic energy of 1.25 × 1051 erg and an initial 56Ni mass of 0.04 M⊙. The resulting SNe produce similar photometric and spectroscopic properties from 10 to 200 d. The spectral characteristics are degenerate. The scatter in early-time color results from the range in progenitor radii, while the differences in late-time spectra reflect the larger oxygen yields in more massive progenitors. Because the progenitors have a comparable H-rich envelope mass, the photospheric phase duration is comparable for all models; the difference in He-core mass is invisible. As different main sequence masses can produce progenitors with a similar H-rich envelope mass, light-curve modeling cannot provide a robust and unique solution for the ejecta mass of type-II-P SNe. The numerous uncertainties in massive-star evolution and wind-mass loss also prevent a robust association with a main sequence star mass. Light-curve modeling can at best propose compatibility.

scholarly journals Review of Contributions to the Workshop on SN1993J

1996 ◽  
Vol 145 ◽  
pp. 241-276
Author(s):  
J. Craig Wheeler ◽  
Alexei V. Filippenko
Keyword(s):  
Gamma Rays ◽  
Electromagnetic Spectrum ◽  
Type Ii ◽  
Spectral Evolution ◽  
X Ray ◽  
Sn 1987A ◽  
Original Mass

At its peak, SN 1993J was one of the brightest supernovae in this century, and it is being studied more thoroughly than any supernova except SN 1987A. It is proving to be similar to the transition object SN 1987K, which metamorphosed from being a hydrogen-rich Type II near peak to having a hydrogen-deficient nebular phase. SN 1993J has been observed throughout the electromagnetic spectrum and with optical spectropolarimetry. It is interacting with a dense circumstellar nebula and is generating radio and X-ray flux, but it has probably not been detected in gamma rays. The photometric and spectral evolution are consistent with a star of original mass ∼ 15 Mʘ that lost appreciable mass to a binary companion leaving an extended, helium-rich hydrogen envelope of ≲ 0.5 Mʘ and a helium core of ∼ 4 Mʘ. The spectral evolution will put strong constraints on the mixing of 66Ni and other species.

scholarly journals Three-dimensional mixing and light curves: constraints on the progenitor of supernova 1987A

2019 ◽  
Vol 624 ◽  
pp. A116 ◽  
Author(s):  
V. P. Utrobin ◽  
A. Wongwathanarat ◽  
H.-Th. Janka ◽  
E. Müller ◽  
T. Ertl ◽  
...  
Keyword(s):  
Light Curve ◽  
Maximum Velocity ◽  
Light Curves ◽  
3D Analysis ◽  
Reverse Shock ◽  
Core Mass ◽  
Single Star ◽  
Sn 1987A ◽  
Supernova 1987A ◽  
Larger Sample

With the same method as used previously, we investigate neutrino-driven explosions of a larger sample of blue supergiant models. The blue supergiants were evolved as single-star progenitors. The larger sample includes three new presupernova stars. The results are compared with light-curve observations of the peculiar type IIP supernova 1987A (SN 1987A). The explosions were modeled in 3D with the neutrino-hydrodynamics code PROMETHEUS-HOTB, and light-curve calculations were performed in spherical symmetry with the radiation-hydrodynamics code CRAB, starting at a stage of nearly homologous expansion. Our results confirm the basic findings of the previous work: 3D neutrino-driven explosions with SN 1987A-like energies synthesize an amount of 56Ni that is consistent with the radioactive tail of the light curve. Moreover, the models mix hydrogen inward to minimum velocities below 400 km s−1 as required by spectral observations and a 3D analysis of molecular hydrogen in SN 1987A. Hydrodynamic simulations with the new progenitor models, which possess smaller radii than the older ones, show much better agreement between calculated and observed light curves in the initial luminosity peak and during the first 20 days. A set of explosions with similar energies demonstrated that a high growth factor of Rayleigh–Taylor instabilities at the (C+O)/He composition interface combined with a weak interaction of fast Rayleigh–Taylor plumes, where the reverse shock occurs below the He/H interface, provides a sufficient condition for efficient outward mixing of 56Ni into the hydrogen envelope. This condition is realized to the required extent only in one of the older stellar models, which yielded a maximum velocity of around 3000 km s−1 for the bulk of ejected 56Ni, but failed to reproduce the helium-core mass of 6 M⊙ inferred from the absolute luminosity of the presupernova star. We conclude that none of the single-star progenitor models proposed for SN 1987A to date satisfies all constraints set by observations.

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