During η Car's spectroscopic event in mid-2003, the stellar wind's bright Hα and Hβ emission lines temporarily had a distinctive shape unlike that reported on any previous occasion, and particularly unlike the 1997--98 event. Evidently the structure of the wind changed between 1997 and 2003. Combining this with other evidence, we suspect that the star may now be passing through a rapid stage in its recovery from the Great Eruption seen 160 years ago. In any case the data indicate that successive spectroscopic events differ, and the hydrogen line profiles are quantitative clues to the abnormal structure of the wind during a spectroscopic event.
@article{arxiv.astro-ph/0410718,
title = {A Change in the Physical State of $\eta$ Carinae?},
author = {K. Davidson and J. C. Martin and R. M. Humphreys and K. Ishibashi and T. R. Gull and O. Stahl and K. Weis and D. J. Hillier and A. Damineli and M. Corcoran and F. Hamann},
journal= {arXiv preprint arXiv:astro-ph/0410718},
year = {2009}
}
Comments
Accepted to appear in the Feb 2005 AJ; 22 pages, including 4 figures and 2 tables