Systems of VO and CaH molecule bands in spectra of stars of spectral type M

1Pavlenko, YV, 2Schmidt, M
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Nicolaus Copernicus University, Torun, Poland
Kinemat. fiz. nebesnyh tel (Online) 2015, 31(2):59-72
Start Page: Physics of Stars and Interstellar Medium
Language: Russian

The absorption of radiation by the CaH and VO molecule band systems in atmospheres of dwarf stars of spectral type M is simulated. These bands form visible spectral details in their spectra. Our calculations used detailed line lists obtained by various investigators. For the CaH molecule, we investigated the relationship between the calculated synthetic spectra and accepted value of dissociation potential. The theoretical energy distributions are compared with the observed fluxes from two known M-dwarfs. The energy distributions for spectra of 2MASS2242-2859 (M5.5 V) and SIPS2039-1126 (M7 IV-V) are reproduced. It is found that the observed energy distributions can be fitted well enough with theoretical spectra calculated for atmosphere models with Tef/lgg/[Fe/H] = 3000/4.5/0 and 2700/4.5/0, respectively. These estimates are consistent with known results of other investigators.

Keywords: CaH and VO molecules, stars of the spectral class M

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