# Fit data with a given function depending on parameters

I want to fit the data of a star's temperature with a function from a model. That function depend on several parameters. I want to know how can I find the value of those parameters.

The data is:

CasA = {{333, 6.3258}, {335, 6.3237}, {337, 6.317}, {340, 6.3127}, {342, 6.3104}}


The function that I'm using is:

Temperature[t_] := Tc/(1 + (t - tc) f/tc)


In the literature there are values for the parameters Tc and tc, however I want to find them using a fitting.

I have been trying changing the parameters by hand, but that looks like a very silly way to do it.

Best, JD