The First Measurement of Stellar Coronal Abundances: \\ The Absence of the FIP Effect in the Corona of Procyon
Session 5 -- Chromospheres/Coronae/Active Binaries
Display presentation, Monday, 30, 1994, 9:20-6:30

## [5.22] The First Measurement of Stellar Coronal Abundances: \\ The Absence of the FIP Effect in the Corona of Procyon

J.J.Drake (CEA/UCB), J.M.Laming (SFA Inc/Nav Res Lab), K.G.Widing (Nav Res Lab), J.H.M.M.Schmitt (MPE), B.Haisch, S.Bowyer (CEA/UCB)

The unique spectroscopic capabilities of the Extreme Ultraviolet Explorer satellite (EUVE), with wavelength coverage from 70--760~\AA\ at a resolution of \$\approx 1\$~\AA, permit for the first time the scrutiny in the extreme ultraviolet wavelength regime of individual spectral lines emitted by the coronae of stars other than the Sun.

We have performed a detailed analysis of the first EUVE spectroscopic observation of the nearby F5 IV star Procyon and have identified lines of the elements O, Ne, Mg, Si, S, Fe, and Ni. The emission measure distribution, derived from line intensities measured from the EUVE spectra and based on the most recent atomic data, has yielded estimates of the relative abundances of these elements in the corona of Procyon. The results indicate a total absence of a fractionation of elements by first ionization potential (FIP), contrary to such as is observed in the solar corona (the ``FIP Effect'').

These results are discussed, and the potential for future EUVE spectroscopic investigation into the new field of stellar coronal abundances is highlighted. This work has been supported by NASA contract NAS5-30180.