SAO: Destroyer of Worlds

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bystander
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SAO: Destroyer of Worlds

Post by bystander » Mon Sep 27, 2010 6:09 pm

Destroyer of Worlds
Smithsonian Astrophysical Observatory
Weekly Science Update | 24 Sept 2010
Astronomers, in addition to discovering extrasolar planets (about 500 of them currently have known orbital parameters), have detected excess, warm infrared dust emission around many stars. This emission, first spotted by the Infrared Astronomy Satellite (IRAS) in the 1980's, appears to come from small particles in disks around the stars that might be in the early stages of planet formation. In some cases, models of the dust temperature and spatial distribution suggest that the disk has a gap, perhaps excavated by a planet at the appropriate orbital distance.

Since planets are made from circumstellar materials, the dust rings in very young systems could be remnants of the planet building process. That dust, however, is thought to disappear after only a few hundred million years; when it is seen in older stellar systems, astronomers surmise, it must have been somehow replenished. One popular scenario is that planets or asteroids in the system collide and fragment, thereby generating the dust. Very old stars, however, (ones that are about a billion years old or more, the sun being about 4.5 billion years old) should not have warm dust according to this reasoning. Those stellar systems should have stabilized, and the time for such collisions should have long past. It is a problem, then, that warm dust is seen around some very old stars. Moreover, since any newly made dust will also rapidly dissipate, there must be some mechanism that regularly regenerates it. Astronomers trying to piece together a coherent history of planet formation and evolution are trying to figure out the answers to these questions.

SAO astronomers Marco Matranga, Jeremy Drake, Vinay Kashyap, and Research Associate Massimo Marengo, together with a colleague, suggest an answer for one set of stars in this puzzle. They used the Spitzer Space Telescope to study the excess warm infrared emission around three evolved stellar systems, each of which is a binary with two stars in close orbits. The measured infrared emission can be as much as 1.9% of the total emission of these systems. They note that the binary stars are known to be magnetically active (surface sun-spots are detected in their atmosphere), and they argue that magnetic fields interacting with winds can induce changes in the binary stars' orbits. These changes can in turn disrupt the overall stability of the system and trigger new collisions between bodies in orbit around the stars, with the consequent production of new dust. In effect, these binary stars are destroyers of the worlds in orbit around them, worlds that otherwise had survived for a billion years. Besides helping to resolve one long-standing puzzle, the new paper points to the complex nature of stellar planetary system, and the importance of multi-wavelength data analyses.
Close Binaries with Infrared Excess: Destroyers of Worlds? - M Maranga et al

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neufer
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Re: SAO: Destroyer of Worlds

Post by neufer » Mon Sep 27, 2010 7:45 pm

bystander wrote:Destroyer of Worlds
Smithsonian Astrophysical Observatory
Weekly Science Update | 24 Sept 2010

SAO astronomers Marco Matranga, Jeremy Drake, Vinay Kashyap, and Research Associate Massimo Marengo, together with a colleague, suggest an answer for one set of stars in this puzzle. They used the Spitzer Space Telescope to study the excess warm infrared emission around three evolved stellar systems, each of which is a binary with two stars in close orbits. They note that the binary stars are known to be magnetically active (surface sun-spots are detected in their atmosphere), and they argue that magnetic fields interacting with winds can induce changes in the binary stars' orbits. These changes can in turn disrupt the overall stability of the system and trigger new collisions between bodies in orbit around the stars, with the consequent production of new dust. In effect, these binary stars are destroyers of the worlds in orbit around them, worlds that otherwise had survived for a billion years. Besides helping to resolve one long-standing puzzle, the new paper points to the complex nature of stellar planetary system, and the importance of multi-wavelength data analyses.
A Birkeland beer :b: shout-out to The Asterisk's own misunderstood EM theorists clique!
Art Neuendorffer

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Ann
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Re: SAO: Destroyer of Worlds

Post by Ann » Tue Sep 28, 2010 3:32 am

neufer wrote:
bystander wrote:Destroyer of Worlds
Smithsonian Astrophysical Observatory
Weekly Science Update | 24 Sept 2010

SAO astronomers Marco Matranga, Jeremy Drake, Vinay Kashyap, and Research Associate Massimo Marengo, together with a colleague, suggest an answer for one set of stars in this puzzle. They used the Spitzer Space Telescope to study the excess warm infrared emission around three evolved stellar systems, each of which is a binary with two stars in close orbits. They note that the binary stars are known to be magnetically active (surface sun-spots are detected in their atmosphere), and they argue that magnetic fields interacting with winds can induce changes in the binary stars' orbits. These changes can in turn disrupt the overall stability of the system and trigger new collisions between bodies in orbit around the stars, with the consequent production of new dust. In effect, these binary stars are destroyers of the worlds in orbit around them, worlds that otherwise had survived for a billion years. Besides helping to resolve one long-standing puzzle, the new paper points to the complex nature of stellar planetary system, and the importance of multi-wavelength data analyses.
A Birkeland beer :b: shout-out to The Asterisk's own misunderstood EM theorists clique!
Why did you highlight that quote in blue, Art? Not that I don't appreciate the color. But who is misunderstood here? Are you suggesting that this is all nonsense?

Ann
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neufer
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Re: SAO: Destroyer of Worlds

Post by neufer » Tue Sep 28, 2010 11:52 am

Ann wrote:
neufer wrote:
bystander wrote:
Smithsonian Astrophysical Observatory: <<SAO astronomers Marco Matranga, Jeremy Drake, Vinay Kashyap, and Research Associate Massimo Marengo, together with a colleague, suggest an answer for one set of stars in this puzzle. They used the Spitzer Space Telescope to study the excess warm infrared emission around three evolved stellar systems, each of which is a binary with two stars in close orbits. They note that the binary stars are known to be magnetically active (surface sun-spots are detected in their atmosphere), and they argue that magnetic fields interacting with winds can induce changes in the binary stars' orbits. These changes can in turn disrupt the overall stability of the system and trigger new collisions between bodies in orbit around the stars, with the consequent production of new dust. In effect, these binary stars are destroyers of the worlds in orbit around them, worlds that otherwise had survived for a billion years. Besides helping to resolve one long-standing puzzle, the new paper points to the complex nature of stellar planetary system, and the importance of multi-wavelength data analyses.>>
A Birkeland beer :b: shout-out to The Asterisk's own misunderstood EM theorists clique!
Why did you highlight that quote in blue, Art? Not that I don't appreciate the color.
But who is misunderstood here? Are you suggesting that this is all nonsense?
Birkeland was underlined & highlighted in blue automatically
(not that I don't appreciate the color)
to indicate that one can click on it to find out more information.

The complex electromagnetic nature of stellar planetary systems boggles the mind of most astronomers (professional & amateur) and I wouldn't begin to start to evaluate such ideas. We all do appreciate it, however, when folks publish such ideas formally rather than presenting them haphazardly in forums such as this simply to befuddle the rest of us.
Art Neuendorffer

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Ann
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Re: SAO: Destroyer of Worlds

Post by Ann » Tue Sep 28, 2010 5:09 pm

Well, thanks for the Birkeland beer, Art. looks good in blue and all, but it tastes Norwegian. At least the name of Anders Celsius gives it a Swedish touch.
The Asterisk's own misunderstood EM theorists clique
:?: :?: :?: :?: :?:

I googled EM theorists and found this:
EM theorists can maintain that sometimes (at least, partially) external states constitute realizer states for some of the standard mental states (e.g., belief, long-term memory). In this case, I argue, the EM hypothesis falls prey to a difference argument; that is, the causal interactions which characterize the behavior of the extended state will not satisfy the functional definitions of the standard mental states.
I think I need a Birkeland beer to make my head stop spinning. Read all about it here:

http://www.bu.edu/conscious/speakers.html

Image
Read all about it!
And have a Birkeland beer, too! Skål!

Ann
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