Answer:
88.0015184nm
Explanation:
By wein's law
λT= 2.898x10^{-3}kelvin meter
where;
λ = wavelenght
T= Temperature (in kelvin)
2.898x10^{-3}mk = Wein's constant
so
λ x T(sun)= 2.898x10^{-3}
550 x 10\small ^{-9}x T (sun) =2.898x10^{-3}
T (sun) = 2.898x10^{-3}/ 550 x 10\small ^{-9}
T (sun) = 5269.09090909 kelvin
T (sun) = 5.269x10^{3}kelvin
Now, Given T( star )= 4 x T (sun)
so,
λ (star) x T( star ) = 2.898x10^{-3}kelvin meter
λ(star) x 4 x T (sun) = 2.898x10^{-3}kelvin meter
λ (star) x 4 x 5.269x10^{3}kelvin = 2.898x10^{-3}kelvin meter
λ(star) = ( 2.898x10^{-3}kelvin meter)/ (4 x 5.269x10^{3}kelvin)
λ (star) = 8.80015184 x 10^{-7}meter
λ (star) = 88.0015184 x 10^{-9}meter
λ (star) = 88.0015184 nm