Solar analogs: Spectral energy distributions and physical parameters of their atmospheres

The angular diameters, radii, and effective temperatures of 16 G0-G5 main-s equence stars with color excesses 0.60 less than or equal to B-V less than or equal to 0.68 and parallaxes derived from Hipparcos data have been deter mined using their infrared fluxes, obtained from JHKLM photometric observat ions. For all the stars except BS 483, these effective temperatures differ from the spectroscopic temperatures by no more than 1-2%. Such differences are within the uncertainties expected for the IR-Aux method. The effective temperatures of BS 483 derived from its infrared fluxes are 3% higher than those indicated by spectroscopic observations; this may be due to the speci fic atmospheric structure of this star. Spectroscopic observations at 3400- 7500 Angstrom and JHKLM photometric observations are compared with analogou s solar data and Kurucz models. The best agreement with the model with T-ef f = 5750 K and logg = 4.5 in the interval 4400-7500 Angstrom was obtained f or BS 7503 and BS 7504 (16 Cyg A and 16 Cyg B). The infrared color indices H - K, K - L, and K - M for these stars differ from the corresponding solar indices, and their angular diameters grow with wavelength, which is not th e case for the Sun. H - K for BS 6060, currently considered to be the close st analog to the Sun, is near the solar value. The vast majority of the sta rs studied (13 of 16) have higher luminosities than the Sun. These include 16 Cyg A, 16 Cyg B, and 51 Peg, which thus cannot be considered full "twins " of the Sun. (C) 2000 MAIK "Nauka/Interperiodica".