scholarly journals Wray 15-906: a candidate luminous blue variable discovered with WISE, Herschel, and SALT

2020 ◽  
Vol 498 (4) ◽  
pp. 5093-5108
Author(s):  
O V Maryeva ◽  
V V Gvaramadze ◽  
A Y Kniazev ◽  
L N Berdnikov
Keyword(s):  
Mass Loss ◽  
Mass Loss Rate ◽  
Stellar Atmosphere ◽  
Wide Field ◽  
Single Star ◽  
V Band ◽  
Spectroscopic Monitoring ◽  
Open Star ◽  
Binary Evolution ◽  
Luminous Blue Variable

ABSTRACT We present the results of study of the Galactic candidate luminous blue variable Wray 15-906, revealed via detection of its infrared circumstellar shell (of ≈2 pc in diameter) with the Wide-field Infrared Survey Explorer and the Herschel Space Observatory. Using the stellar atmosphere code cmfgen and the Gaia parallax, we found that Wray 15-906 is a relatively low-luminosity, $\log (L/\rm \, L_\odot)\approx 5.4$, star of temperature of 25 ± 2 kK, with a mass-loss rate of ${\approx}3\times 10^{-5} \, \rm \, M_\odot \, {\rm yr}^{-1}$, a wind velocity of $280\pm 50 \, {\rm \, km\, s^{-1}}$, and a surface helium abundance of 65 ± 2 per cent (by mass). In the framework of single-star evolution, the obtained results suggest that Wray 15-906 is a post-red supergiant star with initial mass of ${\approx}25 \, \rm \, M_\odot$ and that before exploding as a supernova it could transform for a short time into a WN11h star. Our spectroscopic monitoring with the Southern African Large Telescope does not reveal significant changes in the spectrum of Wray 15-906 during the last 8 yr, while the V-band light curve of this star over years 1999–2019 shows quasi-periodic variability with a period of ≈1700 d and an amplitude of ≈0.2 mag. We estimated the mass of the shell to be $2.9\pm 0.5 \, \rm \, M_\odot$ assuming the gas-to-dust mass ratio of 200. The presence of such a shell indicates that Wray 15-906 has suffered substantial mass-loss in the recent past. We found that the open star cluster C1128−631 could be the birth place of Wray 15-906 provided that this star is a rejuvenated product of binary evolution (a blue straggler).

scholarly journals The influence of stellar wind mass loss on the evolution of massive close binaries.

1979 ◽  
Vol 83 ◽  
pp. 409-414
Author(s):  
D. Vanbeveren ◽  
J.P. De Grève ◽  
C. de Loore ◽  
E.L. van Dessel
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Binary Systems ◽  
Mass Loss Rate ◽  
Radiation Force ◽  
Roche Lobe ◽  
Close Binaries ◽  
Massive Binary Systems ◽  
Binary Evolution ◽  
X Ray Binaries

It is generally accepted that massive (and thus luminous) stars lose mass by stellar wind, driven by radiation force (Lucy and Solomon, 1970; Castor et al. 1975). For the components of massive binary systems, rotational and gravitational effects may act together with the radiation force so as to increase the mass loss rate. Our intention here is to discuss the influence of a stellar wind mass loss on the evolution of massive close binaries. During the Roche lobe overflow phase, mass and angular momentum can leave the system. Possible reasons for mass loss from the system are for example the expansion of the companion due to accretion of the material lost by the mass losing star (Kippenhahn and Meyer-Hofmeister, 1977) or the fact that due to the influence of the radiation force in luminous stars, mass will be lost over the whole surface of the star and not any longer through a possible Lagrangian point as in the case of classical Roche lobe overflow (Vanbeveren, 1978). We have therefore investigated the influence of both processes on binary evolution. Our results are applied to 5 massive X-ray binaries with a possible implication for the existence of massive Wolf Rayet stars with a very close invisible compact companion. A more extended version of this talk is published in Astronomy and Astrophysics (Vanbeveren et al. 1978; Vanbeveren and De Grève, 1978). Their results will be briefly reviewed.

scholarly journals Observational properties of massive black hole binary progenitors

2018 ◽  
Vol 609 ◽  
pp. A94 ◽  
Author(s):  
R. Hainich ◽  
L. M. Oskinova ◽  
T. Shenar ◽  
P. Marchant ◽  
J. J. Eldridge ◽  
...  
Keyword(s):  
Mass Loss ◽  
Binary Systems ◽  
Spectral Characteristics ◽  
Broad Band ◽  
Stellar Atmosphere ◽  
High Mass ◽  
Massive Black Hole ◽  
Synthetic Spectra ◽  
Binary Evolution ◽  
Loss Rates

Context. The first directly detected gravitational waves (GW 150914) were emitted by two coalescing black holes (BHs) with masses of ≈ 36 M⊙ and ≈ 29 M⊙. Several scenarios have been proposed to put this detection into an astrophysical context. The evolution of an isolated massive binary system is among commonly considered models. Aims. Various groups have performed detailed binary-evolution calculations that lead to BH merger events. However, the question remains open as to whether binary systems with the predicted properties really exist. The aim of this paper is to help observers to close this gap by providing spectral characteristics of massive binary BH progenitors during a phase where at least one of the companions is still non-degenerate. Methods. Stellar evolution models predict fundamental stellar parameters. Using these as input for our stellar atmosphere code (Potsdam Wolf-Rayet), we compute a set of models for selected evolutionary stages of massive merging BH progenitors at different metallicities. Results. The synthetic spectra obtained from our atmosphere calculations reveal that progenitors of massive BH merger events start their lives as O2-3V stars that evolve to early-type blue supergiants before they undergo core-collapse during the Wolf-Rayet phase. When the primary has collapsed, the remaining system will appear as a wind-fed high-mass X-ray binary. Based on our atmosphere models, we provide feedback parameters, broad band magnitudes, and spectral templates that should help to identify such binaries in the future. Conclusions. While the predicted parameter space for massive BH binary progenitors is partly realized in nature, none of the known massive binaries match our synthetic spectra of massive BH binary progenitors exactly. Comparisons of empirically determined mass-loss rates with those assumed by evolution calculations reveal significant differences. The consideration of the empirical mass-loss rates in evolution calculations will possibly entail a shift of the maximum in the predicted binary-BH merger rate to higher metallicities, that is, more candidates should be expected in our cosmic neighborhood than previously assumed.

scholarly journals Envelope Distention and Mass Loss IN W VIR Pulsating Variables

1989 ◽  
Vol 111 ◽  
pp. 262-262
Author(s):  
Yu. A. Fadeyev ◽  
H. Muthsam
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Stellar Atmosphere ◽  
Scale Height ◽  
The Other ◽  
Escape Velocity ◽  
Hydrodynamic Calculations ◽  
The Mean ◽  
Radial Pulsations

AbstractThe hydrodynamic calculations of nonlinear self-excited radial pulsations were done for the models of W Vir stars with mass 0.6 M⊙ and luminosities from 794L⊙ to 3981L⊙. The periods of the models are longer than 10 days. The pulsations are shown to be accompanied by periodic shocks that change the density distribution in the pulsating stellar atmosphere. At radii less than 5 Rph, where Rph is the radius of the photosphere, the mean dynamic scale height is nearly five times the static scale height. In this region of the atmosphere the mean radii of outer mass zones do not change perceptably. On the other hand, at radii larger than 5 Rph the scale height is of the order of Rph so that the outermost layers ultimately expand with a velocity exceeding the local escape velocity. The mass flux in the atmosphere increases with decreasing mass to radius ratio and mass loss rate in W Vir type variables is in the range from 2 X 10−6M⊙·yr−1 to 10−5M⊙·yr−1.

scholarly journals Type IIb supernovae by the grazing envelope evolution

2019 ◽  
Author(s):  
Binyamin V Naiman ◽  
Efrat Sabach ◽  
Avishai Gilkis ◽  
Noam Soker
Keyword(s):  
Mass Loss ◽  
Binary Systems ◽  
The Other ◽  
Primary Star ◽  
Single Star ◽  
Common Envelope ◽  
Secondary Star ◽  
The Core ◽  
Free Parameters ◽  
Binary Evolution

Abstract We simulate the evolution of binary systems with a massive primary star of 15M⊙ where we introduce an enhanced mass loss due to jets that the secondary star might launch, and find that in many cases the enhanced mass loss brings the binary system to experience the grazing envelope evolution (GEE) and form a progenitor of Type IIb supernova (SN IIb). The jets, the Roche lobe overflow (RLOF), and a final stellar wind remove most of the hydrogen-rich envelope, leaving a blue-compact SN IIb progenitor. In many cases without this jet-driven mass loss the system enters a common envelope evolution (CEE) and does not form a SN IIb progenitor. We use the stellar evolutionary code MESA binary and mimic the jet-driven mass loss with a simple prescription and some free parameters. Our results show that the jet-driven mass loss, that some systems have during the GEE, increases the parameter space for stellar binary systems to form SN IIb progenitors. We estimate that the binary evolution channel with GEE contributes about a quarter of all SNe IIb, about equal to the contribution of each of the other three channels, binary evolution without a GEE, fatal CEE (where the secondary star merges with the core of the giant primary star), and the single star channel.

scholarly journals The effect of aspherical stellar wind of giant stars on the symbiotic channel of type Ia supernovae

2021 ◽  
Author(s):  
Chengyuan Wu ◽  
Dongdong Liu ◽  
Xiaofeng Wang ◽  
Bo Wang
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Mass Loss Rate ◽  
Binary Interaction ◽  
Opening Angle ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Binary Evolution ◽  
Red Giant ◽  
Ia Supernovae

Abstract The progenitor systems accounting for explosions of type Ia supernovae (SNe Ia) is still under debate. Symbiotic channel is one of the possible progenitor scenarios, in which the WDs in these systems increase in mass through wind accretion from their red giant companions. The mass-loss processes of the giants in the symbiotic systems could produce amount of circumstellar medium (CSM), and detections of interaction signals between SN ejecta and CSM can be used as an ideal way to distinguish different progenitor models. However, the density distribution and geometric structure of the CSM around the symbiotic systems remain highly uncertain. By assuming that the tidal torque from binary interaction can increase the mass-loss rate of the red giant and cause the stellar wind concentrate towards the equatorial plane, we provide a simplified method to estimate the density and the degree of deviation from spherical symmetry for the CSM. Based on the calculations of the binary evolutions of symbiotic systems using stellar evolution code MESA, we obtained the parameter space for producing SNe Ia. We found that SNe Ia could originate from symbiotic systems with massive carbon-oxygen white dwarfs (CO WDs), while the half-opening angle of the stellar wind from red giant towards the WD varies with the binary evolution, resulting in the formation of surrounding CSM with different geometric structures. The corresponding properties of ejecta-CSM interactions may be examined by spectropolarimetry observations in the future, from which one may find additional relationship between circumstellar environment of SNe Ia and their progenitor systems.

scholarly journals The Physical Parameters of Four WC-type Wolf–Rayet Stars in the Large Magellanic Cloud: Evidence of Evolution*

2022 ◽  
Vol 924 (2) ◽  
pp. 44
Author(s):  
Erin Aadland ◽  
Philip Massey ◽  
D. John Hillier ◽  
Nidia Morrell
Keyword(s):  
Spectral Synthesis ◽  
Mass Loss Rate ◽  
Large Magellanic Cloud ◽  
Stellar Atmosphere ◽  
Magellanic Cloud ◽  
Physical Parameters ◽  
Evolutionary Models ◽  
Single Star ◽  
Oxygen Abundance ◽  
Solar Metallicity

Abstract We present a spectral analysis of four Large Magellanic Cloud (LMC) WC-type Wolf–Rayet (WR) stars (BAT99-8, BAT99-9, BAT99-11, and BAT99-52) to shed light on two evolutionary questions surrounding massive stars. The first is: are WO-type WR stars more oxygen enriched than WC-type stars, indicating further chemical evolution, or are the strong high-excitation oxygen lines in WO-type stars an indication of higher temperatures. This study will act as a baseline for answering the question of where WO-type stars fall in WR evolution. Each star’s spectrum, extending from 1100 to 25000 Å, was modeled using cmfgen to determine the star’s physical properties such as luminosity, mass-loss rate, and chemical abundances. The oxygen abundance is a key evolutionary diagnostic, and with higher resolution data and an improved stellar atmosphere code, we found the oxygen abundance to be up to a factor of 5 lower than that of previous studies. The second evolutionary question revolves around the formation of WR stars: do they evolve by themselves or is a close companion star necessary for their formation? Using our derived physical parameters, we compared our results to the Geneva single-star evolutionary models and the Binary Population and Spectral Synthesis (BPASS) binary evolutionary models. We found that both the Geneva solar-metallicity models and BPASS LMC-metallicity models are in agreement with the four WC-type stars, while the Geneva LMC-metallicity models are not. Therefore, these four WC4 stars could have been formed either via binary or single-star evolution.

scholarly journals The Evolution of Massive Close Binary Systems : Estimates of the Parameters Governing Mass and Angular Momentum Loss

1980 ◽  
Vol 88 ◽  
pp. 115-121
Author(s):  
D. Vanbeveren ◽  
C. De Loore
Keyword(s):  
Angular Momentum ◽  
Mass Loss ◽  
Binary Systems ◽  
Mass Loss Rate ◽  
Roche Lobe ◽  
Close Binary ◽  
Close Binaries ◽  
Stellar Winds ◽  
Binary Evolution ◽  
Image Position

It becomes more and more evident that for close binary evolution during Roche lobe overflow as well mass transfer as mass loss occurs. When a mass element ΔM is expelled from the primary during this phase, a fraction β is transferred to the secondary; the remaining part leaves the system. Moreover, angular momentum leaves the system, and also this fraction has to be specified; this fraction is related to a parameter α (Vanbeveren et al., 1979). For the computation of the evolution of massive close binaries also mass loss due to stellar wind of both components, prior to the Roche lobe overflow has to be taken into account. The mass loss rate Ṁ due to radiation driven stellar winds can be expressed as

scholarly journals High-exitation nebulae around Magellanic Wolf-Rayet stars

2008 ◽  
Vol 4 (S256) ◽  
pp. 437-442 ◽  
Author(s):  
Manfred W. Pakull
Keyword(s):  
Binary System ◽  
Mass Loss ◽  
Special Importance ◽  
Interesting Aspect ◽  
Single Star ◽  
Input Parameters ◽  
Low Mass ◽  
Binary Evolution ◽  
Weak Wind ◽  
Loss Rates

AbstractThe SMC harbours a class of hot nitrogen-sequence Wolf-Rayet stars (WNE) that display only relatively weak broad Heiiλ4686 emission indicative of their low mass-loss rates and which are therefore hard to detect. However, such stars are possible emitters of strong He+Lyman continua which in turn could ionize observable Heiiiregions, i.e. highly excited Hiiregions emitting nebular Heiiλ4686 emission. We here report the discovery of a second Heiiiregion in the SMC within OB association NGC 249 within which the weak-lined WN star SMC WR10 is embedded. SMC WR10 is of special importance since it is a single star showing the presence of atmospheric hydrogen. While analysing the spectrum in the framework of two popular, independent WR atmosphere models we found strongly discrepant predictions (by 1 dex) of the He+continuum for the same input parameters. A second interesting aspect of the work reported here concerns the beautiful MCELS images which clearly reveal a class of strongly Oiiiλ5007 emitting (blue-coded) nebulae. Not unexpectedly, most of the “blue” nebulae are known Wolf-Rayet bubbles, but new bubbles around a few WRs are also detected. Moreover, we report the existence of blue nebulae without associated known WRs and discuss the possibility that they reveal weak-wind WR stars with very faint stellar Heiiλ4686 emission. Alternatively, such nebulae might hint at the hitherto missing population of relatively low-mass, hot He stars predicted by massive binary evolution calculations. Such a binary system is probably responsible for the ionization of the unique Heiiλ4686-emitting nebula N 44C.

scholarly journals On the observational behaviour of the highly polarized Type IIn supernova SN 2017hcc

2019 ◽  
Vol 488 (3) ◽  
pp. 3089-3099
Author(s):  
Brajesh Kumar ◽  
Chakali Eswaraiah ◽  
Avinash Singh ◽  
D K Sahu ◽  
G C Anupama ◽  
...  
Keyword(s):  
Loss Rate ◽  
Mass Loss Rate ◽  
Surrounding Medium ◽  
Broad Band ◽  
Polarization Data ◽  
Intrinsic Polarization ◽  
V Band ◽  
Gaia Dr2 ◽  
Luminous Blue Variable ◽  
Narrow Emission

ABSTRACT We present the results based on photometric (Swift UVOT), broad-band polarimetric (V and Rbands) and optical spectroscopic observations of the Type IIn supernova (SN) 2017hcc. Our study is supplemented with spectropolarimetric data available in literature for this event. The post-peak light-curve evolution is slow (∼0.2 mag 100 d−1 in b band). The spectrum of ∼+27 d shows a blue continuum with narrow emission lines, typical of a Type IIn SN. Archival polarization data along with the Gaia DR2 distances have been utilized to evaluate the interstellar polarization (ISP) towards the SN direction which is found to be PISP = 0.17 ± 0.02 per cent and θISP = 140° ± 3°. To extract the intrinsic polarization of SN 2017hcc, both the observed and the literature polarization measurements were corrected for ISP. We noticed a significant decline of ∼3.5 per cent (V band) in the intrinsic level of polarization spanning a period of ∼2 months. In contrast, the intrinsic polarization angles remain nearly constant at all epochs. Our study indicates a substantial variation in the degree of asymmetry in either the ejecta and/or the surrounding medium of SN 2017hcc. We also estimate a mass-loss rate of $\dot{M}$ = 0.12 M⊙ yr−1 (for v$\mathrm{ w}$ = 20 km s−1) which suggests that the progenitor of SN 2017hcc is most likely a luminous blue variable.

scholarly journals AGB mass loss

2011 ◽  
Vol 7 (S283) ◽  
pp. 71-78
Author(s):  
Lee A. Willson ◽  
Qian Wang
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Central Star ◽  
Constant Mass ◽  
Single Star ◽  
The Core ◽  
Maximum Mass Loss ◽  
Loss Formula ◽  
Remnant Mass

AbstractMass loss on the AGB removes most of the envelope and leaves a compact remnant to become a white dwarf and perhaps first the central star of a planetary nebula. The envelope mass provides an upper limit on the material available to form the PN, and the terminal mass loss rate plus the small remnant mass left on the core determines how much of that would still be available to form the PN after the star has evolved far enough to the blue. Given a mass loss formula based on observations or models, we can find the deathline where −dMstar/dt = (M/L) dL/dt and can find the contours of constant mass loss rate on a plot of M vs. L. From such plots we can derive the mass available for a PN and the lowest mass single star that can produce a PN of a given mass. However, some details important for PN formation remain uncertain, including the maximum mass loss rate achieved and the envelope mass left when AGB mass loss ceases.

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