Period luminosity Relation

Dereddening

Any magnitude is susceptible to its environmental factor and redenning due to dust in the line of sight is one of them. One method to deredden your observed magnitudes is to calculate the Weisenheit magnitude.

[ m_W = m - R(m_v - m_I) ]

Metalicity

To correct for the variable star’s metalicity (\(\log[O/H]\)), we fit for this linearly [ m’ = m(P;\alpha, \beta) + Z \Delta\log[O/H] ]

• \(Z\): Metalicity free parameter