filter associated with the magnitude mag1.
The filter identifier filter1 must be at a
shorter wavelength as the filter defined by filter2
filter2
filter associated with the magnitude mag2.
The value must be one of the three filters: 'U', 'B' 'V'.
mag1
zero point corrected magnitude derived from the
deadtime corrected count rate measured in the passband
filter1. This is the brightness which is used
to calculate the colour (mag1-mag2) in the
instrumental system (units: magnitude) .
mag2
zero point corrected magnitude derived from the
deadtime corrected count rate measured in the passband
filter2. This is the brightness which is
transformed into the standard system (units: magnitude).
branch
optional integer parameter, used to select a
colour transformation of a required branch in
the Hertzsprung Russel diagram (equivalent to stars with different
metallicities). The default value (=0) selects the transformation
for main sequence stars.
