How a double sunset might look on the surface of an exoplanet in a binary system (NASA/JPL)
Posted on 10/24/2010 8:14:07 PM PDT by SunkenCiv
By developing a technique called precision astrometry, the researchers have discovered a Jupiter-mass exoplanet orbiting the primary star of the binary system of HR 7162 (or HD 176051), some 49 light-years from Earth. They've called it "Inrakluk."
Astrometry is the study of the precise measurements of the positions and movement of stars. This is the first time the technique has been used to decipher the presence of an exoplanet in the complex dynamics of a binary system. The periodic variation in location of HR 7162 led to the Jupiter-like exoplanet's discovery.
But the very existence of Inrakluk has called into question our understanding about how planetary systems form.
In a one-star system like our solar system, the leading theory as to how the planets formed is through a process called accretion... This is all well and good for a single star, but what if you throw a second star into the mix, like in the HR 7162 binary? The accretion model for planetary formation simply doesn't stick.
When there's a second star orbiting the primary (more massive) star in the binary, according to planetary evolution models, the combined gravitational tugging of both stars hinder the slow accretion of the planets. The planet-building materials are ejected from the system before planets can form. This is one reason put forward that may explain why so few exoplanets have been discovered in binary systems.
However, this new discovery proves that mature Jupiter-like worlds can exist in binaries. The TSU-headed group have challenged the planetary accretion theory as the sole planet-forming mechanism in favor of a faster "gravitational collapse" model.
(Excerpt) Read more at news.discovery.com ...
How a double sunset might look on the surface of an exoplanet in a binary system (NASA/JPL)
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But the very existence of Inrakluk has called into question our understanding about how planetary systems form.tee hee.
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Just lovely.
i would of thought two stars of that size and that proximity would have to merge...
Shades of Star Wars and Tatooine.
bump
interesting
which star does it orbit?
yes it is
I wish! I love sci-fi and always have. Once hooked there is no cheating.
The correct answer is that it orbits the barycentric point of the entire system.
That’ll be 20 dollars.
Wouldn’t it orbit both?
How would that work exactly, a figure 8 orbit?
As the mass of the third object the Jupiter size planet is negligible, the easiest way to understand the problem is to treat it as a two body problem, where you have the entire mass of the two suns centred at the barycenter, and the planet orbiting around both of them.
How do I know this? Both suns are on the same side, and very close to one another. In a figure 8, which is a restricted but possible solution, you’d see sunsets and sunrises on opposite sides of the sky, as the planet would pass between the stars.
http://faculty.ifmo.ru/butikov/ManyBody.pdf
Read this to get a better idea of the different ‘classes’ of possible orbits.
That’ll be another 20 dollars.
It's pretty cheeky to be demanding payment when you haven't answered the question.
Check out the PDF link.
A figure 8 is one of many possibilities of ‘restricted’ orbit values.
The most common orbit is to have the planet orbiting well outside of both stars.
He answered it in post 13. The planet will orbit the point around which both stars also orbit. Since the two stars are fairly close together, the planet will orbit outside both of them, and will have a fairly eccentric orbit. If the stars are widely separated, a figure-8 is possible, though very unlikely.
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