"Solar Focus"

General physics and astronomy discussions not directly related to Celestia
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ajtribick
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"Solar Focus"

Post #1by ajtribick » 31.08.2005, 21:03

In Stephen Baxter's novel Space, he describes a point in space called the "solar focus", where the gravitational field of the sun brings light from a distant star (in the novel, Alpha Centauri) to a focus (presumably this is an effect from general relativity).

Presumably such a point would be quite useful for observing another star system, but my question is how do you calculate where such a point is?

Any help much appreciated, thanks.

Malenfant
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Post #2by Malenfant » 31.08.2005, 22:03

I wondered about this myself after I read it (cracking book, btw - the prequel "Time" is also awesome).

I think the idea was that gravitational lensing from the sun's mass would bring the light from alpha centauri to a focus at that point. So presumably if Alpha C was directly behind the sun relative to the observer, that'd be where lightrays would converge.

I have no clue how to calculate it though...


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