Animated NLTE Synthetic Spectra of Mira--type Variable Stars

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Session 112 -- Models and Synthetic Spectroscopy
Display presentation, Saturday, January 15, 9:30-6:45, Salons I/II Room (Crystal Gateway)

[112.05] Animated NLTE Synthetic Spectra of Mira--type Variable Stars

D.G.Luttermoser (Comp.Sc.Corp.), G.H.Bowen, L.A.Willson (Iowa State U.)

We present a movie showing the time evolution of NLTE synthetic spectra representative of Mira-type variable stars, e.g.\ S~Car (K7--M4 IIIe). The spectra of hydrodynamic models were calculated using PANDORA. The screen is formatted into an upper and a lower panel for comparisons between different thermodynamic and spectral features. The movie begins with a comparison between temperature and macroscopic gas velocity as a function of radius over the complete pulsation cycle. The emergent synthetic spectrum from 2000\AA\ to 18,000\AA\ is then compared to the temperature variations over time. A close up of the H$\gamma$ and Mg~II h \& k lines are compared to temperature variations and then with each other. Finally, temperature and velocity variations are plotted as functions of column mass in order to focus on the inner atmospheric depths. An important feature of our model is the peculiar phase shift between the Balmer and Mg~II lines peak flux, which is observed in actual Mira spectra. Details of the model and the significance of the results will be described in the poster.

Saturday program listing