eta Carinae is a stellar binary system with a period of 5.54 years. It harbors one of the brightest and most massive stars in our galaxy. This paper presents spectroscopic evidence for a fast (up to 2,000 km/s) X-ray outflow of ionized gas launched from eta Carinae just before what is believed to be the binary periastron (point of smallest binary separation). The appearance of this high-velocity component, just as the irregular flares in the X-ray light curve, can not be explained by the simple continuous binary wind interaction, adding to the intrigue of the eta Carinae system.
@article{arxiv.astro-ph/0606251,
title = {A hot transient outflow from eta Carinae},
author = {Ehud Behar and Raanan Nordon and Eyal Ben-Bassat and Noam Soker},
journal= {arXiv preprint arXiv:astro-ph/0606251},
year = {2007}
}