Eta Corina真的要爆了吗？

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  arXiv:1507.07961 [pdf, other]

The X-ray Lightcurve of the Supermassive star eta Carinae, 1996--2014

M. F. Corcoran, K. Hamaguchi, J. K. Liburd, D. Morris, T. R. Gull, T. I. Madura, M. Teodoro, A. F. J. Moffat, N. D. Richardson, C.M.P. Russell, A.M.T. Pollock, S.P. Owocki

Comments: International Workshop on Wolf-Rayet Stars, Potsdam, Germany, 1 - 5 June 2015

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)

Eta Carinae is the nearest example of a supermassive, superluminous, unstable star. Mass loss from the system is critical in shaping its circumstellar medium and in determining its ultimate fate. Eta Car currently loses mass via a dense, slow stellar wind and possesses one of the largest mass loss rates known. It is prone to episodes of extreme mass ejection via eruptions from some as-yet unspecified cause; the best examples of this are the large-scale eruptions which occurred in 19th century. Eta Car is a colliding wind binary in which strong variations in X-ray emission and in other wavebands are driven by the violent collision of the wind of eta Car-A and the fast, less dense wind of an otherwise hidden companion star. X-ray variations are the simplest diagnostic we have to study the wind-wind collision and allow us to measure the state of the stellar mass loss from both stars. We present the X-ray lightcurve over the last 20 years from ROSAT observations and monitoring with the Rossi X-ray Timing Explorer and the X-ray Telescope on the Swift satellite. We compare and contrast the behavior of the X-ray emission from the system over that timespan, including surprising variations during the 2014 X-ray minimum.