Periastron Passage Triggering of the 19th Century Eruptions of Eta Carinae

Abstract

We reconstruct the evolution of η Car in the last two centuries under the assumption that the two 19th century eruptions were triggered by periastron passages and through this reconstruction constrain the binary parameters. The beginning of the lesser eruption (LE) at the end of the 19th century occurred when the system was very close to periastron passage, suggesting that the secondary triggered the LE. We assume that the 1838-1858 great eruption (GE) was triggered by a periastron passage as well. We also assume that mass transferred from the primary to the secondary star accounts for the extra energy of the GE. With these assumptions we constrain the total mass of the binary system to be M = M 1 + M 2 250 M . These higher than commonly used masses better match the observed luminosity with stellar evolutionary tracks. Including mass loss by the two stars and mass transfer from the primary to the secondary we obtain a good match of periastron passages to the two peaks in the light curve of the GE. Based on these findings and a similar behavior of P Cygni, we speculate that major luminous blue variable eruptions are triggered by stellar companions and that in extreme cases a short duration event with a huge mass transfer rate can lead to a bright transient event on timescales of weeks to months (a "supernova impostor").

Supernovae 2016bdu and 2005gl, and their link with SN 2009ip-like transients: another piece of the puzzle

“…Woosley et al 2007), or interactions in a massive binary system (e.g. Kashi & Soker 2010). This latter scenario was also suggested for the impostor SN 2000ch (Pastorello et al 2010).…”

“…Steady winds (Castor, Abbott & Klein 1975;Owocki & Puls 1999;Dwarkadas & Owocki 2002;Lamers & Nugis 2002;Chevalier & Irwin 2011;Moriya et al 2011;Ginzburg & Balberg 2012), enhanced mass-loss due to binary interaction (Kashi 2010;Kashi & Soker 2010;Smith & Frew 2011;Chevalier 2012;Soker 2012;de Mink et al 2013;, or major outbursts caused by stellar instabilities (Humphreys & Davidson 1994;Langer, García-Segura & Mac Low 1999;Woosley, Blinnikov & Heger 2007;Arnett & Meakin 2011;Chatzopoulos & Wheeler 2012;Moriya & Langer 2014;Shiode & Quataert 2014) can all lead to the formation of extended circumstellar environments (for reviews on this topic, see Langer 2012 andSmith 2014). When stars embedded in such dense cocoons explode as supernovae (SNe), they produce the typical observables of interacting SNe: narrow to intermediate-width lines in emission, a blue spectral continuum, and enhanced X-ray, ultraviolet (UV), and radio fluxes (Weiler et al 1986;Chugai 1991;Chevalier & Fransson 1994;Filippenko 1997;Aretxaga et al 1999;Chandra et al 2012Chandra et al , 2015Kiewe et al 2012;Smith et al 2017).…”

Recovery From Giant Eruptions in Very Massive Stars

“…Only a few examples have been observed for sufficient lengths of time, the most famous case being η Car's Great Eruption in the nineteenth century. Some conjectural models suggest interior mechanisms (e.g., Guzik et al 1997;Stothers & Chin 1997;Dwarkadas & Balick 1998;Langer et al 1999;Baraffe et al 2001;Shaviv 2001;González et al 2004González et al , 2010Woosley et al 2007;Smith et al 2011;Chatzopoulos & Wheeler 2012;Shacham & Shaviv 2012;Smith 2013), while others employ tidal intervention by companion stars (Cassinelli 1999;Kashi 2010;Kashi & Soker 2010). The phenomenon may be physically related to LBV eruptions which are much smaller.…”

“…Its luminosity, ejected mass, post-eruption wind and photometric record, etc., are known far better than any other SN impostor (Davidson 2012;Humphreys & Martin 2012, and many references therein). η Car's Great Eruption in 1830-1860 may have been triggered by the companion star near periastron (Kashi & Soker 2010 and references therein), but that possibility has little effect on the subsequent internal physics. This paper concerns post-eruption VMS's in general, not specifically η Car.…”

Using Intermediate-Luminosity Optical Transients (ILOTs) to reveal extended extra-solar Kuiper belt objects

“…ILOTs that harbor AGB or extreme-AGB (ExAGB) pre-outburst stars, were modeled for a single (e.g., Thompson et al 2009) and binary systems (e.g., Kashi & Soker 2010;Soker & Kashi 2011, 2012. The progenitor masses of the AGB ILOTs, M85 OT2006-1 and NGC 300 OT2008-1 were estimates as M 1 < 7M ⊙ and 6 < M 1 < 10M ⊙ , respectively (Ofek et al 2008;Prieto et al 2009).…”