Temperature stratification of the Arcturus atmosphere

1Sheminova, VA
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2013, 29(4):31-60
Start Page: Physics of Stars and Interstellar Medium
Language: Russian

A brief overview of recent results of the red giant Arcturus study is given. Based on the synthesis of extended wings of the H and K Ca II lines, the LTE one-dimensional modeling for the atmospheres of the Arcturus and the Sun as a star is performed. For this spectral region, the local continuum is found to be underestimated, in the average, by 12 % in the Arcturus atlases. The missing opacity effect is, on average, 43 % for Arcturus and 9 % for the Sun. The fudge factor to the continuum opacity at 390.0, 392.5, 395.0, 398.0, 400.0 nm is 2.2, 1.9, 1.7, 1.55, 1.45 for Arcturus and 1.2, 1.2, 1.2, 1.17, 1.15 for the Sun. The simulation results confirmed conclusively the validity of the basic atmospheric parameters for Arcturus, such as Teff = 4286 K, lg g = 1.66, and the estimates for chemical element abundances derived by Ramirez I., Allende Prieto C. [Aph. J.—2011.—743, N 2.—P. 135]. The obtained model of the Arcturus atmosphere is presented in tabular form.

Keywords: Arcturus, atmosphere, red giants

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