Possible Implications of Mass Accretion in Eta Carinae
نویسندگان
چکیده
We apply the previously suggested accretion model for the behavior of the super-massive binary system η Carinae close to periastron passages. In that model it is assumed that for ∼ 10 week near periastron passages one star is accreting mass from the slow dense wind blown by the other star. We find that the secondary, the less massive star, accretes ∼ 2 × 10M⊙. This mass posses enough angular momentum to form a disk, or a belt, around the secondary. The viscous time is too long for the establishment of equilibrium, and the belt must be dissipated as its mass is being blown in the reestablished secondary wind. This processes requires about half a year, which we identify with the recovery phase of η Car. We show that radiation pressure, termed radiative braking, cannot prevent accretion. In addition to using the commonly assumed binary model for η Car, we also examine alternative models where the stellar masses are larger, and/or the less massive secondary blows the slow dense wind, while the primary blows the tenuous fast wind and accretes mass for ∼ 10 week near periastron passages. We end by some predictions for the next event (January-March 2009). Subject headings: (stars:) binaries: general−stars: mass loss−stars: winds, outflows−stars: individual (η Carinae)−accretion, accretion disks
منابع مشابه
Accretion by the Secondary in Eta Carinae during the Spectroscopic Event: I. Flow Parameters
We examine the influence of the gravity of the companion (the secondary) to the massive primary star η Carinae on the winds blown by the primary and the secondary. The two winds collide with each other after passing through two respective shock waves, and escape the system while strongly emitting in the X-ray band. While during most of the 5.5 years orbital period, the companion’s gravity has a...
متن کاملExplaining the Early Exit of Eta Carinae from Its 2009 X-ray Minimum with the Accretion Model
We use the accretion model to explain the early exit of η Car from its 2009 X-ray minimum. In the accretion model the secondary star accretes mass from the primary wind near periastron passage, a process that suppresses the secondary wind. As the shocked secondary wind is responsible for most of the X-ray emission, the accretion process accounts for the X-ray minimum. The early exit from the 20...
متن کاملAccretion-Induced Collimated Fast Wind Model for Eta Carinae
I propose a scenario to account for the fast polar outflow detected to be blown by η Carinae in 2000. The scenario accounts also for the lack of this flow in 1998 and 1999. The scenario is based on the binary nature of η Carinae. The collision of the winds blown by the two stars, in particular near periastron passages, slows down ∼ 5% of the wind blown by η Carinae, i.e., the massive primary st...
متن کاملAccretion onto the Companion of Eta Carinae during the Spectroscopic Event. Iv. the Disappearance of Highly Ionized Lines
We show that the rapid and large decrease in the intensity of high-ionization emission lines from the η Carinae massive binary system can be explained by the accretion model. These emission lines are emitted by material in the nebula around the binary system that is being ionized by radiation from the hot secondary star. The emission lines suffer three months long deep fading every 5.54 year, a...
متن کاملScaled-down Version of the Eta Carinae Great Eruption
We propose that the intermediate luminosity optical transient NGC 300 OT2008-1 was powered by a mass transfer episode from an extreme Asymptotic Giant Branch star to a Main Sequence companion. We find a remarkable similarity of the shapes of the light curves of the several months long NGC 300 OT2008-1 outburst, of the three months long 2002 enigmatic outburst of the B star V838 Mon, and the twe...
متن کامل