[Aavso-photometry] Request Assistance With Determining Extinction Coefficients

[Michael Koppelman]

To create extinction coefficients you need to use a set of stars that  
are "white" (i.e near B-V=0).

So you would need to use the stars in table G.2 in order to find the  
coefficients -- you can't use the stars in table H.4. I don't see the  
stars from G.2 in your spreadsheet.

Cheers,
M.

On May 29, 2009, at 9:47 PM, hannon1000 wrote:

> I have been using the book "Astronomical Photometry" by Henden/ 
> Kaitchuck, 1990 to learn about photometry. I have been able to  
> reproduce the data results for the several examples that I have tried.
>
> One part of the Appendinx H.2 Pulse-Counting Example, has me  
> stymied.  I am able to generate (using spreadsheet) the data in the  
> example up to determining the extinction coefficients. The book says  
> these coefficients were determined by the method outlined in  
> Appendix G.  I understand the messages of Appendix G and I have  
> worked the two examples in Appendix G. When I use the Appendix G  
> method to determine extinction coefficients for the H.2 Pulse- 
> Counting Example, I arrive at results that are different from what  
> Appendix H states I should expect.
>
> Can anyone explain to me what I am missing. My spreadsheet is  
> attached. The sheet labeled as "Data" shows data that matches the  
> example leading up determining the extinction coefficients. The  
> sheet labled as "Ext. Coefficients" shows my effort to calculate the  
> extinction coefficients. The book says:
>
> k'v =  0.209
>
> k'bv = 0.162
>
> k'ub = 0.337
>
> k"bv = -0.088
>
>
> Assistance would be greatly appreciated.
>
> Kevin Hannon
> hannon1000 at comcast.net