Sr II and [Sr II] Emission in the Ejecta of eta Carinae

Abstract:
We have discovered four extremely surprising emission lines of strontiumin ejecta near eta Carinae. Hubble Space Telescope (HST) SpaceTelescope Imaging Spectrograph (STIS) observations made in 1999 show twonarrow features whose wavelengths correspond to the forbiddentransitions of Sr II, and we have found no other plausibleidentification for these lines. The identifications are confirmed by newHST/STIS observations of the same stellar position, in which the Sr IIresonance lines are observed. Moreover, [Ti II, [Ni II, [Mn II, and[Co II lines are unusually strong relative to [Fe II at the sameposition. Based on observations made with the NASA/ESA Hubble SpaceTelescope and supported by STIS IDT GTO 8036 and grant GO 8327 from theSpace Telescope Science Institute. The STScI is operated by theAssociation of Universities for Research in Astronomy, Inc., under NASAcontract NAS 5-26555.