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Old January 15th 19, 05:45 AM posted to sci.astro.amateur
RichA[_6_]
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Default Do "starshades" make sense?

On Monday, 14 January 2019 00:11:54 UTC-5, Chris L Peterson wrote:
On Sun, 13 Jan 2019 16:15:54 -0800 (PST), RichA
wrote:

On Sunday, 13 January 2019 18:36:05 UTC-5, Quadibloc wrote:
On Saturday, January 12, 2019 at 6:30:58 PM UTC-7, RichA wrote:
I get occluding the star, but how would a much, much dimmer planet be seen at
all, even by a large telescope?

Of course, the fact that the telescope is *in space* means that occluding the star
can work just about perfectly. So, since occluding can work just about perfectly,
if the star is fairly nearby, a planet might not be dimmer than, say, one of the
galaxies in the Hubble Deep Field photograph.

John Savard


Mars would be about 2.4E-11 dimmer to us, at the distance of Alpha Centauri I think.


Which would mean around mag 28, which is several times brighter than
the dimmest star Hubble can detect. But the proposed planet hunting
telescope has a larger mirror than the HST. So detecting a Mars-like
planet at over a parsec sounds completely feasible.


They want to combine the starshield with that other plan for the diffractive telescope using a 100 meter diffraction disk. 100-1000 times the resolution of the Hubble.