scholarly journals Pre-explosion Properties of Helium Star Donors to Thermonuclear Supernovae

2021 ◽  
Vol 922 (2) ◽  
pp. 241
Author(s):  
Tin Long Sunny Wong ◽  
Josiah Schwab ◽  
Ylva Götberg
Keyword(s):  
Stellar Evolution ◽  
White Dwarf ◽  
Stellar Atmosphere ◽  
Thermonuclear Supernovae ◽  
Atmosphere Model ◽  
Binary Evolution ◽  
Star Binary ◽  
Helium Star

Abstract Helium star–carbon-oxygen white dwarf (CO WD) binaries are potential single-degenerate progenitor systems of thermonuclear supernovae. Revisiting a set of binary evolution calculations using the stellar evolution code MESA, we refine our previous predictions about which systems can lead to a thermonuclear supernova and then characterize the properties of the helium star donor at the time of explosion. We convert these model properties to near-UV/optical magnitudes assuming a blackbody spectrum and support this approach using a matched stellar atmosphere model. These models will be valuable to compare with pre-explosion imaging for future supernovae, though we emphasize the observational difficulty of detecting extremely blue companions. The pre-explosion source detected in association with SN 2012Z has been interpreted as a helium star binary containing an initially ultra-massive WD in a multiday orbit. However, extending our binary models to initial CO WD masses of up to 1.2 M ⊙, we find that these systems undergo off-center carbon ignitions and thus are not expected to produce thermonuclear supernovae. This tension suggests that, if SN 2012Z is associated with a helium star–WD binary, then the pre-explosion optical light from the system must be significantly modified by the binary environment and/or the WD does not have a carbon-rich interior composition.

scholarly journals Links between Symbiotic and Planetary Nebulae

2004 ◽  
Vol 194 ◽  
pp. 226-227 ◽  
Author(s):  
J. A. López ◽  
K. Escalante ◽  
H. Riesgo-Tirado
Keyword(s):  
Stellar Evolution ◽  
White Dwarf ◽  
Binary Systems ◽  
Large Fraction ◽  
Planetary Nebulae ◽  
Central Star ◽  
Primary Component ◽  
Binary Evolution ◽  
Gaseous Envelope

Planetary nebulae (PNe) represent a well defined stage of stellar evolution, where the characteristics of both, the central star and the gaseous envelope have defined properties. A large fraction of PNe contain binary nuclei, therefore, binary evolution plays an important role in the AGB and proto-planetary stages under certain circumstances. Symbiotic nebulae with extended envelopes (D-type), are identified with binary systems where the primary component is usually a Mira giant and the companion a hot white dwarf. Some of these systems resemble planetary nebulae and as a consequence can lead to misleading interpretations. Here we discuss some relevant links and differences between these two types of nebulae.

scholarly journals Testing Common Envelope Theories with White Dwarf Binaries

2004 ◽  
Vol 194 ◽  
pp. 39-40
Author(s):  
G. Nelemans ◽  
C.A. Tout
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Stellar Evolution ◽  
White Dwarf ◽  
White Dwarfs ◽  
Momentum Balance ◽  
Close Binaries ◽  
Transfer Phase ◽  
Common Envelope ◽  
Binary Evolution

AbstractWe determine the possible masses and radii of the progenitors of white dwarfs in binaries from fits to detailed stellar evolution models and use these to reconstruct the mass-transfer phase in which the white dwarf was formed. We confirm the earlier finding that in the first phase of mass transfer in the binary evolution leading to a close pair of white dwarfs, the standard common-envelope formalism based on energy balance in the system, does not work. A formalism based on angular momentum balance can explain the observations. We extend our analysis to all close binaries with at least one white dwarf component. Comparing the two, we show that the formalism based on angular momentum balance can explain all observations at least as well as the energy formalism.

scholarly journals A Spherical Non‐LTE Line‐blanketed Stellar Atmosphere Model of the Early B GiantεCanis Majoris

1998 ◽  
Vol 498 (2) ◽  
pp. 837-850 ◽  
Author(s):  
J. P. Aufdenberg ◽  
P. H. Hauschildt ◽  
S. N. Shore ◽  
E. Baron
Keyword(s):  
Stellar Atmosphere ◽  
Atmosphere Model

scholarly journals A hot and fast ultra-stripped supernova that likely formed a compact neutron star binary

Science ◽  
2018 ◽  
Vol 362 (6411) ◽  
pp. 201-206 ◽  
Author(s):  
K. De ◽  
M. M. Kasliwal ◽  
E. O. Ofek ◽  
T. J. Moriya ◽  
J. Burke ◽  
...  
Keyword(s):  
Neutron Star ◽  
Kinetic Energy ◽  
Light Curve ◽  
Stellar Evolution ◽  
Binary Systems ◽  
Massive Stars ◽  
Compact Binary ◽  
Compact Binary Systems ◽  
Supernova Explosions ◽  
Star Binary

Compact neutron star binary systems are produced from binary massive stars through stellar evolution involving up to two supernova explosions. The final stages in the formation of these systems have not been directly observed. We report the discovery of iPTF 14gqr (SN 2014ft), a type Ic supernova with a fast-evolving light curve indicating an extremely low ejecta mass (≈0.2 solar masses) and low kinetic energy (≈2 × 1050ergs). Early photometry and spectroscopy reveal evidence of shock cooling of an extended helium-rich envelope, likely ejected in an intense pre-explosion mass-loss episode of the progenitor. Taken together, we interpret iPTF 14gqr as evidence for ultra-stripped supernovae that form neutron stars in compact binary systems.

scholarly journals Pulsating low-mass white dwarfs in the frame of new evolutionary sequences

2018 ◽  
Vol 620 ◽  
pp. A196 ◽  
Author(s):  
Leila M. Calcaferro ◽  
Alejandro H. Córsico ◽  
Leandro G. Althaus ◽  
Alejandra D. Romero ◽  
S. O. Kepler
Keyword(s):  
Stellar Evolution ◽  
Effective Temperature ◽  
Evolutionary Models ◽  
Long Period ◽  
Low Mass ◽  
Complete Set ◽  
Effective Temperatures ◽  
Binary Evolution ◽  
Stellar Masses ◽  
Gravity Mode

Context. Some low-mass white-dwarf (WD) stars with H atmospheres currently being detected in our galaxy, show long-period g(gravity)-mode pulsations, and comprise the class of pulsating WDs called extremely low-mass variable (ELMV) stars. At present, it is generally believed that these stars have thick H envelopes. However, from stellar evolution considerations, the existence of low-mass WDs with thin H envelopes is also possible. Aims. We present a thorough asteroseismological analysis of ELMV stars on the basis of a complete set of fully evolutionary models that represents low-mass He-core WD stars harboring a range of H envelope thicknesses. Although there are currently nine ELMVs, here we only focus on those that exhibit more than three periods and whose periods do not show significant uncertainties. Methods. We considered g-mode adiabatic pulsation periods for low-mass He-core WD models with stellar masses in the range [0.1554–0.4352] M⊙, effective temperatures in the range [6000–10 000] K, and H envelope thicknesses in the interval −5.8 ≲ log(MH/M⋆)≲ −1.7. We explore the effects of employing different H-envelope thicknesses on the adiabatic pulsation properties of low-mass He-core WD models, and perform period-to-period fits to ELMV stars to search for a representative asteroseismological model. Results. We found that the mode-trapping effects of g modes depend sensitively on the value of MH, with the trapping cycle and trapping amplitude larger for thinner H envelopes. We also found that the asymptotic period spacing, ΔΠa, is longer for thinner H envelopes. Finally, we found asteroseismological models (when possible) for the stars under analysis, characterized by canonical (thick) and by thin H envelope. The effective temperature and stellar mass of these models are in agreement with the spectroscopic determinations. Conclusions. The fact that we have found asteroseismological solutions with H envelopes thinner than canonical gives a suggestion of the possible scenario of formation of these stars. Indeed, in the light of our results, some of these stars could have been formed by binary evolution through unstable mass loss.

Validation of asteroseismic fitting with the new white dwarf evolution code

2019 ◽  
Vol 15 (S357) ◽  
pp. 114-118
Author(s):  
Agnès Kim
Keyword(s):  
Stellar Evolution ◽  
White Dwarf ◽  
Equations Of State ◽  
Hydrogen Atmosphere ◽  
La Plata ◽  
Best Fit

AbstractThe new version of the White Dwarf Evolution Code (Bischoff-Kim & Montgomery 2018) overcomes limitations of earlier versions by utilizing MESA modules for the equations of state and opacities, now allowing regions of the model with a mix of helium, carbon, and oxygen. This single improvement allows us to almost exactly replicate models output by other stellar evolution codes. Armed with this new capability, we use as a star to fit, a hydrogen atmosphere white dwarf model from the La Plata group (using the LPCODE). We present results of fitting different subsets of periods for that model. This allows us some validation of our fitting methods, knowing exactly what properties we should be recovering in our best fit model.

Sign in / Sign up

Export Citation Format

Share Document