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I'm having trouble with this question, I think I have this question figured out but my answer is coming out incorrect... Tell me if there is a flaw in my logic.. question is:

"Suppose that a luminous star of radius R1=1.74×108 m is surrounded by a uniform atmosphere extending up to a radius R2=4.28×108 m and with index of refraction n=1.82. When the sphere is viewed from a location far away in vacuum, what is its apparent radius?"

What I did was consider the outer edge of the atmosphere a spherical refracting surface.. and using the equation: n1/P + n2/q = (n2-n1)/R

(sorry for not using latex)

And then I took a point from the star's surface, and take the distance form the atmosphere to that point the image distance (where P is just R2 - R1).

I also took n1 as 1.82 and n2 as 1 since it's just vacuum.. and according to the sign conventions the radius should be negative..

After I got the image distance (which was negative, a virtual image), I subtracted it's absolute value from R2, and that should be apparent radius. Am I wrong?

Thx,

Xeno

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# Homework Help: Optics Problem: What am I doing wrong?

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