L15 Flux in flat atmospheres

Week 9, Tuesday

Material covered and references

We generally cannot use Limb-Darkening measurement for stars other than our Sun, as we cannot resolve their surface (but see e.g. here.

However, we know that the total flux (integrated over all wavelengths) should be equal to \(\sigma*T_\mathrm{eff}^4\) (60 MW/m2) at all layers. We use the formal solution to find an expression for the \(F(\lambda)\), which is the integral over all optical depth of the source function multiplied by an Exponential integral function (see illustration in slides).

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