Skip to comments.High-tech imaging reveals atmospheric composition of multiple exoplanets
Posted on 04/03/2013 7:02:27 PM PDT by SunkenCiv
While the number of exoplanets so far identified is steadily marching towards the 1000 mark, fewer than twenty have been discovered in the course of direct observation by astronomical telescopes. Four of them (HR 8977 b,c,d,and e) circle an unprepossessing A5 star called HR 8977, which lies about 130 light-years distant from Earth. Thanks to the little-known astrophysics research arm of the American Museum of Natural History (AMNH), we now have the ability to examine the makeup of their atmospheres by taking simultaneous spectrographs of all four planets...
To convey an idea of how difficult it is to image exoplanets with a telescope, imagine there's a planet called planet "J" that is the twin of Jupiter orbits HR 8977 at the same distance the real Jupiter orbits around the Sun. From HR 8977's distance of 130-light years, the apparent separation between HR 8977 and J would be 0.14 arcsec (seconds of arc), which could be resolved by the Hubble space telescope or ground-based scopes with adaptive optics.
The real problem is that J would be enormously dimmer than HR 8977, which appears from Earth as a sixth magnitude star, barely visible to the unaided eye. J would appear at magnitude +27, about 250 million times fainter than the star. An isolated star with this brightness is just detectable in ground-based telescopes, but not when it is 0.14 arcsec distant from a second star 250 million times brighter...
The main factor making it possible to see the planets of HR 8977 is that they are hot about 900-1100 K. The planets are gas giants several times more massive than Jupiter, and they are quite young in fact, HR 8977 itself appears to be only about 30 million years old, although not all astronomers agree.
(Excerpt) Read more at gizmag.com ...
Project 1640 image of the four exoplanets orbiting HR 8977. The image has been enhanced for clarity (Photo: American Museum of Natural History)
Another extra one.
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Invent warp drive andlet earth rot as a socialist hell hole.....
That’s very pretty. But wouldn’t they all fall together and become one huge mass and turn into a sun or something?
Doesn’t matter. I’m saving it. [smiles]
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