# Table Atmospheres¶

When the `atm_option`

control is set to `'table'`

, MESA uses
pre-computed tables from separate model atmosphere calculations to
interpolate \(T_{\rm surf}\) and \(P_{\rm surf}\) values for
the boundary conditions. The interpolations are peformed using
\(T_{\rm eff}\) and \(\log g\) as independent variables. The
`atm_table`

control determines the choice of table, as follows:

Value | Meaning |

`'photosphere'` |
Use model atmosphere tables computed for a range of metallicites, via a combination of PHOENIX (Hauschildt et al. 1999a,b) and Castelli & Kurucz (2003) treatments. Surface optical depth is defined so that \(T(\tau_{\rm surf}) = T_{\rm eff}\). |

`'tau_100'` |
Use model atmosphere tables computed for solar metallicites, via a combination of COND (Allard et al. 2001) and Castelli & Kurucz (2003) treatments. Surface optical depth is \(\tau_{\rm surf} = 100\). |

`'tau_10'` |
Same as `'tau_100'` , except that surface optical depth is
\(\tau_{\rm surf} = 10\). |

`'tau_1'` |
Same as `'tau_100'` , except that surface optical depth is
\(\tau_{\rm surf} = 1\). |

`'tau_1m1'` |
Same as `'tau_100'` , except that surface optical depth is
\(\tau_{\rm surf} = 0.1\). |

`'WD_tau_25'` |
Use model atmospheres for cool white dwarfs, via Rohrmann et al. (2011, MNRAS, 411, 781) treatment. Surface optical depth is \(\tau_{\rm surf} = 25.12\). |

`'DB_tau_25'` |
Use model atmospheres for hot(ter) white dwarrfs, provided by Odette Toloza based on Detlev Koester’s atmosphere code. Surface optical depth is \(\tau_{\rm surf} = 25.12\). |

When any of these `'table'`

choices is used, it’s possible that the
requested \(T_{\rm eff}\) and \(\log g\) lie outside the table
range. When this happens, MESA can optionally switch to an alternative
approach for evaluating \(T_{\rm surf}\) and \(P_{\rm
surf}\). The `atm_off_table_option`

control determines the
alternative approach adopted, as follows:

Value | Meaning |

`'T_tau'` |
Use the same \(T(\tau)\) approach as described in the
T(tau) Atmospheres section. The `atm_T_tau_relation` and
`atm_T_tau_opacity` controls (and others) are used in this case
for the off-table evaluation. |

If the `atm_off_table_option`

control is left blank, an attempt to interpolate
off the table will cause MESA to halt execution.