[Aavso-photometry] Multi-color photometry

[Brian C. Barnes]

Michael,

    That makes sense. Which transformation coefficients to apply is
determined in part by the quality of the COMP star data you have for each
band.

    In your case, for example, if you did use B-V, you might actually
degrade your computed V value by introducing a noisier element into the
equation.

    When you calculate your transformation coefficients in the first place,
do you record the S/N of the comp stars used, or the "fit" of the resultant
slopes, for later reference when deciding which ones to apply to subsequent
data?

Brian.

-----Original Message-----
From: Michael Koppelman [mailto:lolife at bitstream.net] 
Sent: Thursday, November 03, 2005 12:56
To: Brian C. Barnes
Cc: 'AAVSO Photometry'
Subject: Re: [Aavso-photometry] Multi-color photometry

Yes, you can do this. Usually, though, you'll have the best S/N in  
certain bandpasses and should just use those. For my system, for  
example, I don't use B-V to determine V, I use V-R or V-I because my  
B data is always worse. I could get V from both and average them.

Michael