Extinction correction (photometry)

[learningastronomy]

Homework Statement

I am learning photometry and I am wondering is the uncorrected extinction instrumental magnitude always less than the corrected extinction instrumental magnitude when applying transformation coefficients?

Relevant Equations

$m_{\lambda}^A=m_{\lambda}+[\kappa_0+\kappa_1 (B-V)]X$

For example suppose the uncorrected extinction instrumental magnitude is $v^A_V = 9.00$, will the corrected extinction instrumental magnitude always be greater than $9$?

 

[phyzguy]

Extinction causes an object to be fainter, because some of the light coming from the object is absorbed. So the corrected magnitude should always be brighter than the uncorrected magnitude. So the corrected magnitude will always be less than the uncorrected magnitude, since brighter objects have smaller magnitudes.