Datatype: da

The Delta a photometric system has be designed by Maitzen to detect photometrically peculiar stars (Ap). The original system is based on photoelectric photometry. It uses three filters : g1, g2 and y and the parameter a is defined as

a = g2 - [(g1 + y) / 2].

Δa is computed relatively a linear relation : a versus (B-V) or (b-y).

Record structure

No:Star number
Ref:Data source
a:a parameter
Da:Deviation from the normal relation

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Last Update: 22 January 2006