Answer
The apparent brightness by inverse square law is [tex]3.25*10^-^9watt/m^2[/tex]
Explanation:
b = L / ( 4 pi d^2 )
b = apparent brightness of the star (in watts/meter2)
L = luminosity of the star (in watts)
d = distance to the star (in meter)
pi = approximately 3.14159265
[tex]Given\\d=10 light years=9.461*10^1^6\\L=3.8*10^2^6watts[/tex]
put all values in formula
[tex]b=(3.8*10^2^6)/4*3.14*(9.641*10^1^6)^2[/tex]
[tex]b=3.25*10^-^9watts/m^2[/tex]
