Modelling the spectrum and SED of V838 Mon

We model the spectra and spectral energy distribution of V838 Mon which were observed in February, March, and November, 2002. Theoretical spectra are calculated using the classical model atmospheres taking into account absorption of atomic and molecular lines. By fitting the observed spectra we determine the physical parameters of the atmosphere of V838 Mon. These parameters are determined to be Teff = 5330 +/- 300 K, 5540 +/- 270 K, 4960 +/- 190 K, and 2000 +/- 200 K for February 25, March 2, March 26, and November 6, respectively.