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Full-Text Articles in Physical Sciences and Mathematics
A Sea Change In Eta Carinae, Andrea Mehner, Kris Davidson, Roberta M. Humphreys, John C. Martin, Kazunori Ishibashi, Gary J. Ferland, Nolan R. Walborn
A Sea Change In Eta Carinae, Andrea Mehner, Kris Davidson, Roberta M. Humphreys, John C. Martin, Kazunori Ishibashi, Gary J. Ferland, Nolan R. Walborn
Physics and Astronomy Faculty Publications
Major stellar-wind emission features in the spectrum of η Car have recently decreased by factors of order 2 relative to the continuum. This is unprecedented in the modern observational record. The simplest, but unproven, explanation is a rapid decrease in the wind density.
High-Excitation Emission Lines Near Eta Carinae, And Its Likely Companion Star, Andrea Mehner, Kris Davidson, Gary J. Ferland, Roberta M. Humphreys
High-Excitation Emission Lines Near Eta Carinae, And Its Likely Companion Star, Andrea Mehner, Kris Davidson, Gary J. Ferland, Roberta M. Humphreys
Physics and Astronomy Faculty Publications
In order to study the distribution of gas and ionizing radiation around η Car and their implications for its likely companion star, we have examined high-excitation emission lines of [Ne III], [Fe III], etc., in spectra obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph instrument during 1998-2004. Our principal results, some of them unexpected, are as follows. (1) The high-excitation fluxes varied systematically and non-trivially throughout η Car's 5.5 year spectroscopic cycle. Instead of rising to a plateau after the 1998 ''event,'' they changed continuously with a maximum in mid-cycle. (2) At one significant location a brief, strong …