A Change in the Physical State of Eta Carinae?
Davidson, K.; Martin, J.; Humphreys, R. M.; Ishibashi, K.; Gull, T. R.; Stahl, O.; Weis, K.; Hillier, D. J.; Damineli, A.; Corcoran, M.; Hamann, F.
AA(University of Minnesota), AB(University of Minnesota), AC(University of Minnesota), AD(Center for Space Research, Massachusetts Institute of Technology), AE(NASA/Goddard), AF(Landessternwarte Heidelberg, Königsstuhl), AG(Astronomisches Institut, Ruhr-Universität Bochum), AH(University of Pittsburgh), AI(IAG, University of São Paulo), AJ(NASA/Goddard), AK(University of Florida)
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 1997-1998 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.
Reference: Davidson et al. 2005, AJ, 129, 900
Status: Manuscript has been accepted