[Aavso-photometry] Calculation of Transforms, K' and ZP

[Brian D. Warner]

Jeff,

PhotoRed does not produce the "old standard" mu/epsilon, which presume color-index 
transforms instead of single color (still based on color index differences, however). 
My book covers the methods applied in PhotoRed, so I'm not going to go into detail 
here.

For one, Steve did not use the Landolt magnitudes for his calculations but those 
based on J-K conversions which I developed for "close enough" work to calibrate 
night-to-night work for asteroid lightcurves, i.e,. _internal_ system and not 
Johnson-Cousins standard.

Second, there is considerable scatter in his data when applying the Hardie method for 
first order extinction, probably due to using those conversions. This lead to bad FOE 
values.

I'm working with Steve to go through the tutorials in PhotoRed that do use Henden 
fields for finding FOE and transforms, and then compare what's done there to what 
he's trying to do with his own images and data. Something is getting lost in 
translation <g>


Clear Skies,
Brian D. Warner
Palmer Divide Observatory/Space Science Institute
http://www.MinorPlanetObserver.com

Collaborative Asteroid Lightcurve Link (CALL)
http://www.MinorPlanetObserver.com/astlc/default.htm