SIMBAD references

The atmospheric parameters of 34 hot subdwarf B stars have been obtained using a combination of 61 short and long-wave IUE spectra, together with new and existing optical and infrared photometric data. Using a grid of high-gravity helium-deficient model atmospheres and a χ²-minimization procedure, 15 single sdB stars and 19 composite systems, containing a hot subdwarf B star and a cool main-sequence companion, were analyzed. From the (logL-logT_eff) diagram of our results, we conclude that the majority of the cool companions to our sample of binary sdB stars are main sequence stars, in the range of 4000<T_eff/K<6000 and mass 0.8<M/M_☉<1.3. The lower limit on detectability of cool stars in composite sdB of our sample is ∼3600K, corresponding to a spectral type of M1 or later (Lang, 1992, Astrophysical data: Stars and planets (Springer-Verlag, New York)).