[Aavso-photometry] Transform coefficients and two-filter measurements

[Michael Koppelman]

Thank you Dr. Newberry.

But to Tom's original question, I don't think there are 4 degrees of  
freedom, there are only 2.

So, not this:

- B filter bandpass is bluer than ideal
- B filter bandpass is redder than ideal
- V filter bandpass is bluer than ideal
- V filter bandpass is redder than ideal

This:

- B-V is bluer than ideal
- B-V is redder than ideal

Yes?

M.


On Jul 23, 2009, at 12:07 AM, Michael Newberry wrote:

> Are you asking if it is possible for the graph of b-v vs B-V to have  
> curvature? It so, the answer is yes---it depends on the filter/ 
> detector bandpasses. The transformations are linear over the range  
> of spectral types if the bandpasses are an exact match to the  
> standard system. But as the filters move off the standard  
> bandpasses, in wavelength and shape, nonlinearities creep in.