A New Verification of T$_{eff}$, g, and C/O for $\mu$ Gem

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Session 45 -- Stellar Activity I
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

[45.12] A New Verification of T$_{eff}$, g, and C/O for $\mu$ Gem

T.R.Young (WSU), D.R.Alexander (WSU)

T$_{eff}$, g, and C/O are determined by fitting the observed spectrum of \linebreak $\mu$ Gem, spectral class M3 III, from 3000 $\AA$ to 3 $\mu$m. The emergent spectrum calculated from the model atmospheres code, ATLAS8, uses the most comprehensive list of low temperature opacities (Alexander and Ferguson, 1994, Ap.J., in press) which includes atomic lines, molecules, and grains (68 million lines in all). Results show that the T$_{eff}$ can be well determined by the strength of the TiO bands and the shape of the continuum in the visible. Little effect is seen in the IR when T$_{eff}$ is changed from 3400 to 3700 K. Log(g)=1.0 is found to be consistent with other studies. A high C/O ratio (greater than 0.95) is strictly ruled out in the models when compared to the TiO bands. The allowable range in the C/O ratio, determined from comparison of the TiO bands in the visible, is from 0.44 to 0.85. Models are also compared to the BVRIJKL band observations and to the Wing spectrophotometric observations. Prelimiary results of a theoretical study of M, S, and C giants show that the new list of low temperature opacities will give better determinations of T$_{eff}$, g, and C/O ratio.

This research is supported by NSF grant AST-9217946.

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