Destroyer of worlds

September 24, 2010
An optical image of a ring of dust, possibly in the process of forming planets, around a nearby young star; the bright star itself has been masked out. New results from infrared studies suggest even old stars can generate dusty rings by triggering destructive collisions between bodies orbiting around them. Credit: NASA/Hubble Space Telescope

( -- 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, 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 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 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 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.

Explore further: Two unusual older stars giving birth to second wave of planets

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not rated yet Sep 24, 2010
Could not the unbalanced gravitational pull and the solar winds from two suns keep planets from forming?
5 / 5 (1) Sep 24, 2010
I thought and please don;t rate this but feel free to correct me -- i thought that in a sufficeintly large system the gravity of binary stars would pull on planets toward a center of gravitational mass... like averaging the two ...

but upon reflecting --- when doing the equations to figure out the moon's position you incoporate the sin and cos parameters of all the large bodies in the solar system -- i guess thinking of a binary system like a really big less dense ball is totally the undergraduate explanation....
2.3 / 5 (6) Sep 24, 2010
Is the dust perhaps stellar debris from the explosion of the precursor star?

That seems to be the way the Sun formed on the core of a precursor star and the planets formed out of the chemically and isotopically heterogeneous stellar debris ["Strange xenon, extinct superheavy elements and the solar neutrino puzzle", Science 195, 208-209 (1977); "Isotopes of tellurium, xenon and krypton in the Allende meteorite retain record of nucleosynthesis", Nature 277, 615-620 (1979); "Noble gas anomalies and synthesis of the chemical elements", Meteoritics 15, 117-138 (1980); "Heterogeneity of isotopic and elemental compositions in meteorites: Evidence of local synthesis of the elements " {In Russian}, Geokhimiya (12) 1776-1801 (1981); etc.].

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo
not rated yet Sep 25, 2010
Just as the moons orbit is moving further from the earth over time, is the earth's orbit around the sun also changing? At some time in the future, will the distance between earth and the outer planet become smaller?
Could a sun with many more planets that exist in our solar system exist? Could collisions between these planets occur over the lifetime of that solar system?
Lots of questions to be answered.
1 / 5 (3) Sep 25, 2010
... hadron jet 0 perma corona 1 planade image lunar geddon photon separate image ion pen TOP umbra tope atlas angular period firmament perma 0 jet eclip 2 image type halo arma gluon aurora ...
3 / 5 (1) Sep 26, 2010

A few days ago on "That's impossible" this was discussed in a round about way.

Their conclusions were that given enough time, the earth would eventually escape the sun for several self-reinforcing reasons:

1) As the sun burns it's hydrogen a small fraction of it's mass is converted to energy in the form of light and other radiation, thus decreasing it's gravity.

2) Over time the solar wind was said to potentially reduce the Sun's mass by as much as 25%.

3) The radiation pressure and solar wind from the Sun should exert a small amount of acceleration on the earth through time, pushing it away from the Sun.

the above was based on the "standard model" of the solar system in which they believe the Sun is about 40% through it's life cycle and will go through two phases as a Red Giant star.
not rated yet Oct 05, 2010
I wonder if the astronomers involved call this the Vishnu effect..."Now I am become Death, the destroyer of worlds" - Bhagavad-Gita
3 / 5 (1) Oct 07, 2010

You seem to be right, but does the effects really contribute to the whole?
1) Will this decrease in mass produce a significantly difference in mass and thus a significantly difference in gravitational pull?

2) over time, this is indeed a large difference, true (I haven't checked it though)

3) Yup, if it can power a spaceship, it can also potentially move a planet. Although also here I think the effect is not noticable.

Something else you have left out. The sun will become bigger (in diameter, not mass, so density will become smaller) due to the "burn phase" it is in (when it starts to burn larger atoms than hydrogen, helium etc). This will dramatically increase its radius, probably extended to the asteroid belt. So Earth will not escape, also not when giving time. Jupiter will probably been blown away, its core most likely going into the sun (gas giant, gas blown away, mass significantly lower, will plumet into the sun).
Im afraid earth is lost forever.

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