Hey I have this question and I am wrestling with it all day and I am completely lost.
The V magnitude of a star is 15.1, B-V =1.6, and absolute magnitude Mv= 1.3 The extinction in the direction of the star in the visual band is av = 1 mag/kpc. What is the intrinsic colour?
Can somebody help me?
Edit: Ok, apparently I have to calculate first the distance and after that the excess colour and then I can calculate the intristic colour.
I guess I need this formula for the distance: V = Mv + 5log(r/10pc) + Av But if i fill this in and get the R I get a different r and I dont know what the next step if to go to the excess colour.