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Exoplanet Discoveries



 
 
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  #1  
Old January 13th 12, 03:39 PM
Elassoto Elassoto is offline
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Default Exoplanet Discoveries

The Kepler telescope is discovering many planets by searching for changes in a star's brightness when a planet transits across the face of a star. However, with that method of observing planets, we cannot see any of the details of the planet. While Kepler may not be powerful enough to see details of the planet, maybe future telescopes, such as James Webb will. To see the details it will have to see the bright side of the planet, so it will have to see the planets while they are on the far side of the star. To do that they can use solar occlusion so that the light from the star will not interfere with the light from the planet. The diagram below shows how it could work.
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  #2  
Old January 18th 12, 11:09 PM posted to sci.astro
Steve Willner
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Default Exoplanet Discoveries

In article ,
Elassoto writes:
The Kepler telescope is discovering many planets by searching for
changes in a star's brightness when a planet transits across the face of
a star. However, with that method of observing planets, we cannot see
any of the details of the planet.


Kepler gives the planet's orbital parameters, its diameter, and
sometimes information on the mass if there are multiple planets.

While Kepler may not be powerful
enough to see details of the planet, maybe future telescopes, such as
James Webb will.


If you are talking about resolving the planet's disk, I don't think so.

To see the details it will have to see the bright side
of the planet, so it will have to see the planets while they are on the
far side of the star.


More generally, one would like to track the brightness of the planet
around its orbit. The Spitzer Space Telescope has already done some
of that. It has also observed secondary transits for quite a few
planets now. This gives the infrared emission of the day side of the
planet, which can tell something about the planet's composition or
atmosphere.

To do that they can use solar occlusion


You seem to be talking about a coronagraph, which JWST will have:
http://www.stsci.edu/jwst/instrument.../#coronagraphy
It's actually quite a bit trickier than just putting a black spot in
the focal plane.

A very few exoplanets have already been directly imaged by ground-
based telescopes.

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  #3  
Old January 19th 12, 04:09 PM
Elassoto Elassoto is offline
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Default

Thank you for that excellent information and article. I hope that JWST makes some nice discoveries for us.
  #4  
Old February 9th 12, 06:43 PM posted to sci.astro
Yousuf Khan[_2_]
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Default Exoplanet Discoveries

On 13/01/2012 10:39 AM, Elassoto wrote:
The Kepler telescope is discovering many planets by searching for
changes in a star's brightness when a planet transits across the face of
a star. However, with that method of observing planets, we cannot see
any of the details of the planet. While Kepler may not be powerful
enough to see details of the planet, maybe future telescopes, such as
James Webb will. To see the details it will have to see the bright side
of the planet, so it will have to see the planets while they are on the
far side of the star. To do that they can use solar occlusion so that
the light from the star will not interfere with the light from the
planet. The diagram below shows how it could work.


Some exoplanets have already been imaged by the Hubble and various
terrestrial telescopes. But of course, they are all gas giants, and
pretty far away from their stars. And even still, the images are really
nothing more than fuzzy pixels.

Astronomers Capture First Exoplanet Images : Discovery Space
http://dsc.discovery.com/space/im/ex...ra-seager.html

Yousuf Khan
  #5  
Old February 9th 12, 09:47 PM posted to sci.astro
Brad Guth[_3_]
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Posts: 15,176
Default Exoplanet Discoveries

On Jan 13, 7:39*am, Elassoto wrote:
The Kepler telescope is discovering many planets by searching for
changes in a star's brightness when a planet transits across the face of
a star. However, with that method of observing planets, we cannot see
any of the details of the planet. While Kepler may not be powerful
enough to see details of the planet, maybe future telescopes, such as
James Webb will. To see the details it will have to see the bright side
of the planet, so it will have to see the planets while they are on the
far side of the star. To do that they can use solar occlusion so that
the light from the star will not interfere with the light from the
planet. The diagram below shows how it could work.

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|Download:http://www.spacebanter.com/attachment.php?attachmentid=3905|
+-------------------------------------------------------------------+

--
Elassoto


Yes, we need those remote starshades (solar occlusion) to assist all
forms of astronomy.

http://translate.google.com/#
Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”

  #6  
Old February 9th 12, 09:50 PM posted to sci.astro
Brad Guth[_3_]
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Posts: 15,176
Default Exoplanet Discoveries

On Jan 19, 8:09*am, Elassoto wrote:
Thank you for that excellent information and article. I hope that JWST
makes some nice discoveries for us.

+-------------------------------------------------------------------+
+-------------------------------------------------------------------+

--
Elassoto


Most of us well be quite dead or at least bankrupt by the time it gets
going. Are you happy now?
  #7  
Old February 23rd 17, 02:44 PM
Elassoto Elassoto is offline
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First recorded activity by SpaceBanter: Jan 2012
Location: Boca Raton
Posts: 7
Default

Space telescopes are having trouble seeing planets next to brighter stars. It sounds like stellar coronagraphs can only help so much, but why? Is light still getting around the the stellar corongraphs?
 




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