scholarly journals Wave-Driven Mass Loss: A mechanism for late-stage stellar eruptions

2011 ◽  
Vol 7 (S279) ◽  
pp. 391-392
Author(s):  
Josh Shiode ◽  
Eliot Quataert
Keyword(s):  
Mass Loss ◽  
Gravity Waves ◽  
Stellar Evolution ◽  
Internal Gravity Waves ◽  
Core Collapse ◽  
Sound Waves ◽  
Stellar Envelope ◽  
The Core ◽  
Convective Motions ◽  
Late Stages

AbstractDuring the late stages of stellar evolution in massive stars (carbon fusion and later), the fusion and neutrino luminosities in the core of the star exceed the Eddington luminosity. This can drive vigorous convective motions which in turn excite a super-Eddington flux in internal gravity waves. We show that an interesting fraction of the energy in excited gravity waves can, in some cases, convert into sound waves as the gravity waves propagate (tunnel) towards the stellar surface. The subsequent dissipation of the sound waves can unbind up to several M⊙ of the stellar envelope. This wave-driven mass loss can explain the existence of extremely large stellar mass loss rates just prior to core-collapse, which are inferred via circumstellar interaction in some core-collapse supernovae (e.g., SNe 2006gy and PTF 09uj).

scholarly journals Radio Supernovae as Direct Evidence of Stellar Evolution in Real Time

1998 ◽  
Vol 11 (1) ◽  
pp. 367-367
Author(s):  
S.D. Van Dyk ◽  
M.J. Montes ◽  
K.W. Weiler ◽  
R.A. Sramek ◽  
N. Panagia
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Loss Rate ◽  
Direct Evidence ◽  
Mass Loss Rate ◽  
X Ray ◽  
Stringent Constraint ◽  
Clear Change ◽  
Late Stages ◽  
Circumstellar Environment

The radio emission from supernovae provides a direct probe of a supernova’s circumstellar environment, which presumably was established by mass-loss episodes in the late stages of the progenitor’s presupernova evolution. The observed synchrotron emission is generated by the SN shock interacting with the relatively high-density circumstellar medium which has been fully ionized and heated by the initial UV/X-ray flash. The study of radio supernovae therefore provides many clues to and constraints on stellar evolution. We will present the recent results on several cases, including SN 1980K, whose recent abrupt decline provides us with a stringent constraint on the progenitor’s initial mass; SN 1993J, for which the profile of the wind matter supports the picture of the progenitor’s evolution in an interacting binary system; and SN 1979C, where a clear change in presupernova mass-loss rate occurred about 104 years before explosion. Other examples, such as SNe 19941 and 1996cb, will also be discussed.

scholarly journals Enhanced mass-loss rate evolution of stars with ≳18 M⊙ and missing optically observed type II core-collapse supernovae

2020 ◽  
Vol 494 (4) ◽  
pp. 5230-5238
Author(s):  
Roni Anna Gofman ◽  
Naomi Gluck ◽  
Noam Soker
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Main Sequence ◽  
Mass Loss Rate ◽  
Core Collapse ◽  
Type Ii ◽  
Instability Strip ◽  
Stellar Envelope ◽  
Explosion Mechanism ◽  
Hydrogen Mass

ABSTRACT We evolve stellar models with zero-age main-sequence (ZAMS) mass of MZAMS ≳ 18 M⊙ under the assumption that they experience an enhanced mass-loss rate when crossing the instability strip at high luminosities and conclude that most of them end as type Ibc supernovae (SNe Ibc) or dust-obscured SNe II. We explore what level of enhanced mass-loss rate during the instability strip would be necessary to explain the ‘red supergiant problem’. This problem refers to the dearth of observed core-collapse supernovae progenitors with MZAMS ≳ 18 M⊙. Namely, we examine what enhanced mass-loss rate could make it possible for all these stars actually to explode as core-collapse supernovae (CCSNe). We find that the mass-loss rate should increase by a factor of at least about 10. We reach this conclusion by analysing the hydrogen mass in the stellar envelope and the optical depth of the dusty wind at the explosion, and crudely estimate that under our assumptions only about a fifth of these stars explode as unobscured SNe II and SNe IIb. About 10–15 per cent end as obscured SNe II that are infrared-bright but visibly very faint, and the rest, about 65–70 per cent, end as SNe Ibc. However, the statistical uncertainties are still too significant to decide whether many stars with MZAMS ≳ 18 M⊙ do not explode as expected in the neutrino driven explosion mechanism, or whether all of them explode as CCSNe, as expected by the jittering jets explosion mechanism.

scholarly journals The origin of the two populations of blue stragglers in M30

2019 ◽  
Vol 621 ◽  
pp. L10 ◽  
Author(s):  
S. Portegies Zwart
Keyword(s):  
Stellar Evolution ◽  
Main Sequence ◽  
The Other ◽  
Core Collapse ◽  
Blue Stragglers ◽  
The Core ◽  
Constant Rate ◽  
Blue Straggler ◽  
Binary Evolution ◽  
Two Populations

We analyze the position of the two populations of blue stragglers in the globular cluster M30 in the Hertzsprung–Russell diagram. Both populations of blue stragglers are brighter than the cluster’s turn-off, but one population, the blue blue-stragglers, aligns along the zero-age main sequence whereas the other, red population is elevated in brightness (or color) by ∼0.75 mag. Based on stellar evolution and merger simulations we argue that the red population, which composes about 40% of the blue stragglers in M 30, has formed at a constant rate of ∼2.8 blue stragglers per gigayear over the last ∼10 Gyr. The blue population on the other hand formed in a burst that started ∼3.2 Gyr ago at a peak rate of 30 blue stragglers per gigayear with an e-folding time scale of 0.93 Gyr. We speculate that the burst resulted from the core collapse of the cluster at an age of about 9.8 Gyr, whereas the constantly formed population is the result of mass transfer and mergers through binary evolution. In this scenario, about half the binaries in the cluster effectively result in a blue straggler.

scholarly journals The Impact of Realistic Red Supergiant Mass Loss on Stellar Evolution

2021 ◽  
Vol 922 (1) ◽  
pp. 55
Author(s):  
Emma R. Beasor ◽  
Ben Davies ◽  
Nathan Smith
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Massive Stars ◽  
Light Curves ◽  
Core Collapse ◽  
Strong Impact ◽  
Type Ii ◽  
Evolutionary Models ◽  
Cool Star ◽  
The Impact

Abstract Accurate mass-loss rates are essential for meaningful stellar evolutionary models. For massive single stars with initial masses between 8 and 30M ⊙the implementation of cool supergiant mass loss in stellar models strongly affects the resulting evolution, and the most commonly used prescription for these cool-star phases is that of de Jager. Recently, we published a new M ̇ prescription calibrated to RSGs with initial masses between 10 and 25 M ⊙, which unlike previous prescriptions does not overestimate M ̇ for the most massive stars. Here, we carry out a comparative study to the MESA-MIST models, in which we test the effect of altering mass loss by recomputing the evolution of stars with masses 12–27 M ⊙ with the new M ̇ -prescription implemented. We show that while the evolutionary tracks in the HR diagram of the stars do not change appreciably, the mass of the H-rich envelope at core collapse is drastically increased compared to models using the de Jager prescription. This increased envelope mass would have a strong impact on the Type II-P SN lightcurve, and would not allow stars under 30 M ⊙ to evolve back to the blue and explode as H-poor SN. We also predict that the amount of H-envelope around single stars at explosion should be correlated with initial mass, and we discuss the prospects of using this as a method of determining progenitor masses from supernova light curves.

scholarly journals Evidence for Stellar Evolution in Mira Variables

1998 ◽  
Vol 11 (1) ◽  
pp. 356-356
Author(s):  
Patricia A Whitelock
Keyword(s):  
Mass Loss ◽  
Real Time ◽  
Time Evolution ◽  
Stellar Evolution ◽  
Evolutionary Status ◽  
Late Type ◽  
Chemical Changes ◽  
Mira Variables ◽  
Late Stages ◽  
Insight Into

After briefly reviewing our understanding of Miras and their evolutionary status, three aspects of real-time evolution in these and related stars are examined: 1.Chemical changes (O-rich to C-rich) due to third dredge-up,2.Period changes due to the effects of the helium shell-flash,3.The existence of ‘fossil’ dust and gas shells. Studies of resolved gas and dust shells are highlighted as particularly interesting. They will enable us to examine the mass-loss histories of many late-type stars over the last ten thousand years or so. Such observations have only recently become technically feasible and they are expected to provide important new insight into the late stages of stellar evolution.

scholarly journals Stellar evolution with SMC chemical abundances

1981 ◽  
Vol 59 ◽  
pp. 279-282
Author(s):  
P. Hellings ◽  
D. Vanbeveren
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Binary Systems ◽  
Massive Stars ◽  
Close Binary ◽  
Evolutionary Computations ◽  
Chemical Abundances ◽  
Hydrogen Burning ◽  
The Core ◽  
Early Case

Evolutionary computations are presented for massive stars between 20 Mo and 100 Mo with chemical abundances holding for the Small Magellanic Cloud, i.e. X = .76 and Z = .003. Mass loss by stellar wind is taken into account during core hydrogen burning. After core hydrogen burning some models are considered as members of close binary systems and are followed during their Roche lobe overflow stage according an early case B of mass transfer. During the core helium burning stage of the RL0F remnants mass loss rates comparable to WR stars are included in order to study the formation and the evolution of WR stars. Comparison with similar galactic computations (Vanbeveren, Packet, 1978) is made.

scholarly journals Radiation hydrodynamical simulations of eruptive mass loss from progenitors of Type Ibn/IIn supernovae

2020 ◽  
Vol 635 ◽  
pp. A127 ◽  
Author(s):  
Naoto Kuriyama ◽  
Toshikazu Shigeyama
Keyword(s):  
Mass Loss ◽  
Massive Star ◽  
Massive Stars ◽  
Circumstellar Matter ◽  
Core Collapse ◽  
The Core ◽  
Actual Mechanism ◽  
Nuclear Burning ◽  
Hydrodynamical Simulations ◽  
Extract Information

Context. Observations suggest that some massive stars experience violent and eruptive mass loss associated with significant brightening that cannot be explained by hydrostatic stellar models. This event seemingly forms dense circumstellar matter (CSM). The mechanism of eruptive mass loss has not been fully explained. We focus on the fact that the timescale of nuclear burning gets shorter than the dynamical timescale of the envelope a few years before core collapse for some massive stars. Aims. To reveal the properties of the eruptive mass loss, we investigate its relation to the energy injection at the bottom of the envelope supplied by nuclear burning taking place inside the core. In this study, we do not specify the actual mechanism for transporting energy from the site of nuclear burning to the bottom of the envelope. Instead, we parameterize the amount of injected energy and the injection time and try to extract information on these parameters from comparisons with observations. Methods. We carried out 1D radiation hydrodynamical simulations for progenitors of red, yellow, and blue supergiants, and Wolf–Rayet stars. We calculated the evolution of the progenitors with a public stellar evolution code. Results. We obtain the light curve associated with the eruption, the amount of ejected mass, and the CSM distribution at the time of core-collapse. Conclusions. The energy injection at the bottom of the envelope of a massive star within a period shorter than the dynamical timescale of the envelope could reproduce some observed optical outbursts prior to the core-collapse and form the CSM, which can power an interaction supernova classified as Type IIn.

scholarly journals The IAC morphological catalog of Northern Galactic Planetary Nebulae

1997 ◽  
Vol 180 ◽  
pp. 24-25 ◽  
Author(s):  
A. Manchado ◽  
M. A. Guerrero ◽  
L. Stanghellini ◽  
M. Serra-Ricart
Keyword(s):  
Magnetic Fields ◽  
Mass Loss ◽  
Stellar Evolution ◽  
Morphological Study ◽  
Planetary Nebulae ◽  
Asymptotic Giant Branch ◽  
Intermediate Mass ◽  
Evolutionary Scheme ◽  
Late Stages

Planetary Nebulae (PNs) are highly representative of the late stages of intermediate mass stellar evolution. However, there are still many unresolved questions in their evolutionary scheme. Mass loss processes during the Asymptotic Giant Branch (AGB) are not fully understood. Binarity, rotation and magnetic fields may play an important role in PNs formation. The morphological study of PNs will help us to address those questions, and therefore a meaningful homogeneous database is needed.

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