Mass Loss: Its Effect on the Evolution and Fate of High-Mass Stars

“Since massive stars have short lifetimes, their ultraviolet (UV) radiation (reprocessed in various forms) is the most observable tracer of star formation and is used to calculate the star formation rates (Kennicutt 1998, Kennicutt & Evans 2012).”

“Perhaps new open-source codes like MESA (Paxton et al. 2011) will facilitate this.”

“This single-star paradigm then permitted one to extend even further, to compute models for the collective radiative output of entire stellar populations as a function of age (e.g., codes like starburst99; Leitherer et al. 1999).”

“Later, estimates for the solar wind (Parker 1958) powered by hot gas pressure had such low mass-loss rates that winds would not matter much in stellar evolution.”

“Since massive stars have short lifetimes, their ultraviolet (UV) radiation (reprocessed in various forms) is the most observable tracer of star formation and is used to calculate the star formation rates (Kennicutt 1998, Kennicutt & Evans 2012).”

“They leave behind exotic corpses such as black holes, neutron stars, pulsars, magnetars, and all the bizarre high-energy phenomena that occur when compact objects remain bound in a binary system (e.g., Remillard & McClintock 2006).”

“The fact that GRB progenitors have shed most of their envelopes while still retaining a great deal of angular momentum (MacFadyen & Woosley 1999) would seem to strongly favor their origin in binary evolution with mass transfer to spin up the star, or even a merger.”

“…very massive, and they made the first SNe, the first stellar mass black holes, the first dust, ejected the first metals back into the ISM, enhanced or dominated reionization, and probably triggered the formation of the earliest generations of low-mass stars (Bromm & Larson 2004, Heger et al. 2003).”

“…from several young clusters suggest that, when corrected for obervational bias, the fraction of massive stars in binary systems whose orbital period is so short that the stars must exhange mass or merge is something like 3/4 (Kiminki & Kobulnicky 2012, Kobulnicky & Fryer 2007, Sana et al. 2012).”

“…observed location in the Hertzsprung-Russell (HR) diagram is important in order to calibrate stellar evolutionary models for massive stars and to understand their further evolution toward WR stars and supernovae (e.g., Dessart et al. 2013; Groh et al. 2013, 2014; Smith 2014; Meynet et al. 2015).”

“Fluctuations in the mass-loss rate over these timescales, short compared to the age of the star, have been seen or inferred in a number of stars (e.g. Smith 2014).”

“Such a value is much larger than the typical mass-loss rate of 10−6–10−5 M yr−1 for red supergiants (RSGs) (Smith 2014).”

“For example, mass loss in these stars has been plagued by uncertainties—its driving mechanisms in the early or late stages of nuclear burning are todate not well understood (Smith 2014).”

“Assuming that this eruption corresponds to the first CSM listed in Table 2, the wind velocity vwind can be derived, namely ( ) = + -v R z1 60.58 yr 42 km swind out,1 1, which is slightly higher than the observed wind velocity of Type II-P SNe (Smith 2014).”

“This excludes the densest winds that have been observed around some supergiant stars (Smith 2014), though we note that the constraint applies only along the line of sight and dense but asymmetric gas from e.g. binary interaction is allowed (Dong et al. 2021).”

“Several channels may be responsible for the pre-SN mass loss, including binary interaction, stellar wind, or a combination of both (Heger et al. 2003; Sana et al. 2012; Groh et al. 2013; Smith 2014; Yoon 2015; Fang et al. 2019).”

“…and theoretical evidence has revealed our lack of understanding of whether or not they explode after core collapse, what evolutionary stage they explode in, and what the resulting supernova ( SN ) explosion looks like ( e.g., Smith 2014; Smartt 2015; Sukhbold et al. 2018; Neustadt et al. 2021 ) .”

“Our grid selection for MCS is largely driven by published observations of nebular shells around massive, LBV–type stars indicating MCS ' 0.1–20 M (Smith & Owocki 2006; Groh et al. 2009; Wachter et al. 2010; Gvaramadze et al. 2010; Smith 2014).”

“Massive stars are known to lose their own envelopes due to the radiation pressure throughout their lives (e.g., Castor, Abbott, & Klein 1975; Smith & Owocki 2006), leading to the formation of circumstellar matter (CSM) with a variety of density structures (see Smith 2014).”

“The study of these observables gives us important clues to the progenitors’ mass-loss rates, hence constraining the late evolution of massive stars (see, e.g., Smith 2014).”

“Observations in the past decade provide evidence that binary interaction (Podsiadlowski et al. 1992) is the primary mechanism for producing the majority of SESN progenitors (Eldridge et al. 2013; see reviews by Smith 2014, 2017).”

“…material (CSM) from late pre-collapse outbursts in a significant number of observed supernovae (for an overview, see Foley et al. 2011; Smith 2014; Bilinski et al. 2015; Smith 2017), although other mechanisms such as flashes from degenerate shell burning (Woosley & Heger 2015) or the…”

“Smith (2014) estimated that eruptive luminous blue variable (LBV) progenitors can have mass-loss rates in the range of 0.01–10 M yr −1, while even very massive red supergiant or yellow hypergiant progenitors have mass-loss rates in the range of 10−4–10−3 M yr −1.”

“The natures of progenitor stars with such mass loss rates range from red supergiants to luminous blue variables (Smith 2014).”

“Mass transfer is one of the essential processes in interacting binary stars that dramatically changes the post-main-sequence evolution (e.g., Iben 1991; Taam & Sandquist 2000; Yoon et al. 2010; Langer 2012; Smith 2014).”

“…especially massive stars; however, the number of observed SESNe is too high to explain the majority with such high-mass stars ( Smith et al. 2011; Smith 2014; Sravan et al. 2019; Dessart et al. 2020 ) , and traditional stellar wind prescriptions cannot readily explain the high mass loss rates…”

“The density of the wind followed an ∼ r−2 profile consistent with the observed properties of RSG–type winds (see Figure 3 in Smith (2014)).”

“…stars and Wolf-Rayet (WR) stars (e.g. HD94; Maeder & Meynet 2000) or is an intermediate precursor of a supernova (e.g. Smith et al. 2007, 2008, 2011; Trundle et al. 2008; Gal-Yam & Leonard 2009; Groh, Meynet & Ekström 2013; Mauerhan et al. 2013; see more details in the review paper by Smith 2014).”

“This mass loss will directly influence the evolution and death of massive stars since a star’s mass will dictate its power output, effective temperature, and nucleosynthetic products (Smith 2014).”

“Very massive stars with initial masses above 100 M may lose much of their mass in violent pre-supernova (SN) eruptions, which profoundly affect the appearance of spectra and lightcurves in the subsequent SN (Smith 2014).”

“For CC SNRs, the argument is even stronger, as mass-loss is often the single most uncertain ingredient in stellar evolution models for SN progenitors (Smith, 2014).”

“The sustained late-time luminosity of some SNe II can be explained by interaction of the SN shock with large amounts of CSM set up by the pre-SN wind (e.g., Fox et al. 2013; Smith 2014, 2017; Smith et al. 2017).”

“Disentangling these effects remains a major difficulty in understanding massive star formation and (co-)evolution (e.g., Langer 2012; Smith 2014).”

“…with a separation of  1 au, the proximity of the stars generally gives rise to interactions via mass transfer, and their evolution will diverge from that of a single star ( e.g., P. Podsiadlowski et al. 1992; N. Langer 2012; H. Sana et al. 2012; N. Smith 2014; O. De Marco & R. G. Izzard 2017 ) .”

“Single-star wind-driven mass loss cannot explain either the rate or the low progenitor mass observed in most SESNe, and binary-driven mass loss likely produces most of the SESN progenitors ( e.g., Smith 2014 for a review ) .”

“The peak magnitude of average Type IIn SNe is estimated to be MV = −18.4±1.0 (Kiewe et al. 2012), with more recent estimates (Richardson et al. 2014; Nyholm et al. 2020) giving consistent results.”

“High levels of mass loss also affects the evolution of massive stars, in particular the nature of their remnants (Puls et al. 2008; Langer 2012; Smith 2014).”

“In fact, bright emission found in a special class of SNewith prominent hydrogen narrow lines in their spectra, SNe IIn (see, e.g., Filippenko 1997; Smith 2014, for a review), is explained by the hydrodynamical interaction.”

“Accordingly, it has been the subject of a number of studies (see, e.g., the reviews on mass-loss by Puls et al. 2008; Smith 2014).”

“…progenitors are es- Corresponding author: Takashi J. Moriya takashi.moriya@nao.ac.jp timated to be more than ∼ 10−4 M⊙ yr−1 (e.g., Kiewe et al. 2012; Taddia et al. 2013; Moriya et al. 2014; Fox et al. 2013; Ofek et al. 2014a) which is beyond the mass-loss rates of ordinary stars (e.g., Smith 2014).”

“Evolutionary models show that large mass loss rates profoundly affect the ultimate state of the star, while the momentum input strongly affects the stellar environment (e.g., Langer 2012; Smith 2014).”

“Massive stars are known to undergo intense terminal mass loss episodes which remain poorly understood (Groh et al. 2013; Smith 2014).”

“The type of supernovae that a massive star will become is primarily determined by its initial mass, metallicity, as well as its mass-loss rate (MLR) during the RSG phase (Humphreys 2010; Ekstr¨om et al. 2013; Smith 2014; Meynet et al. 2015; Beasor & Davies 2018).”

“We are not sure (Smith 2014), and that is why we have to explore different evolutionary stages to understand when mass loss happens.”

“The formation of SNe is closely related to the end-of-life evolution of massive stars, which is a phase of stellar evolution that remains poorly constrained [239].”

“It is also much larger than the typical values of RSG and yellow hypergiants (10 − 4 − 10 − 3 M ⊙ yr − 1 ; Smith 2014), and quiescent winds of LBV (10 − 5 − 10 − 4 M ⊙ yr − 1 , Vink 2018).”

“The evolution of massive stars into RSGs and the duration of this phase are sensitive to stellar internal mixing and wind mass loss during the RSG phase, both of which are still not well understood (Schootemeijer et al. 2019; Yoon & Cantiello 2010; Smith 2014; Zapartas et al. 2024).”

“Massive stars play host to some of the most unusual stellar phenomena, including rapid mass loss (Smith 2014), time-varying UV emission (Ramiaramanantsoa et al. 2014), strong magnetic fields (Sundqvist et al. 2013), stochastic low-frequency variability (Bowman 2020), rotational mixing (Maeder &…”

“…supernovae: general, supernovae: individual: SN 2017hcc INTRODUCTION Type IIn supernovae (SNe) are a heterogenous class of stellar explosions associated with the deaths of massive stars surrounded by dense circumstellar environments created by strong mass-loss episodes (e.g., Smith 2014).”

“Most other LBVs have quiescent mass-loss rates in the range 10 − 6 to 10 − 4 M ⊙ yr − 1 (Smith, 2014).”

“Due to their high luminosities and large escape velocities, massive stars launch fast ( v w ≳ 10 3 km / s), line-driven stellar winds (e.g., see reviews by Smith 2014; Vink 2022).”

“…of outbursts of astrophysical systems that eject mass in response to the deposition of energy near the stellar surface, such as classical novae (Gallagher & Star-rfield 1978), Type IIn supernova progenitors (Cheva-lier 1988; Kochanek 2011; Smith 2014), and X-ray bursts (Gottwald et al. 1986).”

“Due to complex mechanisms, such as mass loss, internal mixing and magnetic field effects (see reviews by Langer 2012; Smith 2014), predicting and understanding the evolution of stars with masses > 8 M remains a challenge.”

“…likely from single origin and therefore useful to explore the physics of supernovae (e.g., Fryer et al. 2012), such as fallback (e.g., Vigna-Gómez et al. 2021) and the pair-instability mass gap (e.g., Heger & Woosley 2002; Woosley 2017), as well as stellar winds (e.g., Smith 2014, for a review).”

“The last stages of the evolution of the most massive (M30 Me) stars may be dominated by episodic large mass ejections (e.g., Humphreys & Davidson 1984; Smith 2014).”

“Moreover, as the stellar evolution is sensitive to the mass loss (Smith 2014), the amount of mass lost in each stage affects the subsequent evolu- ar X iv :2 00 8.”

“In the case of a single massive (>20 M☉) Wolf-Rayet star, the radiationdriven stellar wind is the dominant process (see Woosley et al. 1995; Massey 2003; Crowther 2007; Smith 2014; Yoon 2015, and references therein).”

“While mass loss is one of the key mechanisms regulating the evolution of massive stars, a complete understanding of it is still missing, specially during the final phases before the supernova (SN) explosion (e.g., Smith 2014).”

“Assuming that the mass lost from winds is much less than the total mass in the system (Fullerton et al. 2006; Smith 2014), we can estimate the change in angular momentum due to winds as ∆Jwind loss ≈ ∆M∗R 2 ∗ω∗, and that gained from spin up as ∆Jspin up ≈ M∗R 2 ∗ω∗(∆(a)/a).”

“R stars: M M˙ 10 yrWR 4 1< − ⊙ − (Crowther 2007; Smith 2014).”

“The systematic biases in observed mass loss rates depend on choice of line diagnostic, as ρ2 diagnostics such as Hα are especially sensitive to wind “clumpiness” (Kudritzki & Puls 2000; Smith 2014).”

“Although poorly understood, episodic mass loss may play an important role in stellar evolution (Smith & Owocki 2006; Smith 2014), at least for a subset of stars in interacting binaries (Smith & Tombleson 2015; Aghakhanloo et al. 2017).”

“CSM–Ejecta Interaction + Radioactive Decay Model (CSM+RD) An exploding star could possibly be surrounded by dense CSM formed through stellar winds, giant eruptions, binary interaction, or a pulsational pair instability (Smith 2014; Woosley 2017, and references therein).”