Spherically Symmetric Model Atmospheres for Low‐Mass Pre–Main‐Sequence Stars with Effective Temperatures between 2000 and 6800 K

We present a grid of spherically symmetric model atmospheres for young pre-MS stars. This grid spans the parameter range 2000\ \≤ \ \≤ 6800\ and 2.0 \≤ \ \≤ 3.5 for M=0.1\, appropriate for low mass stars and brown dwarfs. A major improvement is the replacement of TiO and \\\ line lists with the newer line list calculated by the NASA-AMES group, for TiO (about 175 million lines of 5 isotopes) and for \\\ (about 350 million lines in 2 isotopes). We provide the model structures, spectra and broad-band colors in standard filters in electronic form.