By Daniel Stolte, University Communications June 10, 2010
For the first time, astronomers have observed solar systems in the making in great detail.
- Like a raindrop forming in a cloud, a star forms in a diffuse gas cloud in deep space. As the star grows, its gravitational pull draws in dust and gas from the surrounding molecular cloud to form a swirling disk called a “protoplanetary disk.” This disk eventually further consolidates to form planets, moons, asteroids and comets. (Credit: NASA/JPL-Caltech)
A team led by University of Arizona astronomer
Joshua Eisner has observed in unprecedented detail the processes giving rise to stars and planets in nascent solar systems.
The discoveries, published in theAstrophysical Journal, provide a better understanding of the way hydrogen gas from the protoplanetary disk is incorporated into the star.
By coupling both Keck telescopes on Mauna Kea in Hawaii with a specifically engineered instrument named ASTRA (ASTrometric and phase-Referenced Astronomy), Eisner and his colleagues were able to peer deeply into protoplanetary disks – swirling clouds of gas and dust that feed the growing star in its center and eventually coalesce into planets and asteroids to form a solar system.
The big challenge facing Eisner’s team lies in obtaining the extremely fine resolution necessary to observe the processes that happen at the boundary between the star and its surrounding disk – 500 light years from Earth. It’s like standing on a rooftop in Tucson trying to observe an ant nibbling on a grain of rice in New York’s Central Park.
“The angular resolution you can achieve with the Hubble Space Telescope is about 100 times too coarse to be able to see what is going on just outside of a nascent star not much bigger than our sun,” said Eisner, an assistant professor at UA’s Steward Observatory. In other words, even a protoplanetary disk close enough to be considered in the neighborhood of our solar system would appear as a featureless blob.
Combining the light from the two Keck telescopes provides an angular resolution finer than Hubble’s. Eisner and his team used a technique called spectro-astrometry to boost resolution even more. By measuring the light emanating from the protoplanetary disks at different wavelengths with both Keck telescope mirrors and manipulating it further with ASTRA, the researchers achieved the resolution needed to observe processes in the centers of the nascent solar systems.
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Quote “swirling clouds of gas and dust that feed the growing star in its center and eventually coalesce into planets and asteroids to form a solar system.”
If this is how our solar system evolved, how can the sun be mainly hydrogen, and the planets have all the elements of the Periodic Table? Shades of Oliver Manuel.
Objection. Relevance?
Like many of our sacred cows, scientific dogma promotes and protects whatever ideology that is currently supported by the mainstream. This ensures “peer” acceptance in more than just publications. Ideally, financial motivation could be limited by ensuring that investigation be unfettered and equally provided for. Not in the real world, unfortunately…
The only thing we know for sure is that the challenge lies in challenging orthodoxy.
The big difference with relevancy is the billions of $$$ that are involved for the scientists and the trillions of $$$ that are in play through political policy and industrial maneuvering. Thankfully, we have arrived not in an age of reason but in an age of information and dissemination is what counts.
Jim Cripwell says:
June 12, 2010 at 4:01 am
Good question. Could it be that the greater angular momentum of the heavier elements kept them further out? Only speculation, but when you swirl things around, eg in a centrifuge, this happens, but I have not looked at the physics of a solar system.
Relevance? From the masthead, it’s part of “life, nature, science…” and general coolness. 🙂
All heavier elements are formed in nucleuses of the Galaxy’s stars; some ended in supernovae explosions and were blasted away, to later form planets by gravitation attraction. Meteorites with pre-solar carbon have been found in Central Africa and Brazil.
Jbar says:
June 12, 2010 at 5:43 am
Objection. Relevance?
Yup – seconded
>> Jim Cripwell says:
June 12, 2010 at 4:01 am
If this is how our solar system evolved, how can the sun be mainly hydrogen, and the planets have all the elements of the Periodic Table? Shades of Oliver Manuel. <<
The gas is mostly hydrogen, with less than 10% helium and trace amounts of other gasses. The dust includes ices and is an insignificant fraction of the total, although it's significant enough to make planets. Imagine a star of just hydrogen and helium, then drop Earth and Venus into it. Afterwards its still mostly just hydrogen and helium. The gas component that didn't become part of the sun (or Jovian planets) was blown out of the solar system long ago.
The atmospheres of the rocky planets (mostly H2O and CO2) were from ices that accreted in planet formation and were later outgassed. The argon came from the decay of potassium 40, and helium from alpha decay. Oxygen in Earth's atmosphere is biological. I still haven't heard a good explanation of the nitrogen.
An manned observatory on a lunar pole would be most effective, and a worthy project for the USA.
Where has our ambition gone?
http://www.ulb.ac.be/scmero/optic_membrane.html
Relevance? Why not? Do we always have to talk about the weather/climate? I rather liked this piece.
Jbar says:
June 12, 2010 at 5:43 am
Objection. Relevance?
hoho. Never let it be said I leave the low hanging fruits…
Look at the banner, Jbar, see the words? The magical words that explain the purpose and focus of this site? Nature and Science are included, so – leaving aside that its Anthony’s site and he can do pretty much what he wants, this little topic is pretty much covered and is interesting, no?
Jbar says:
June 12, 2010 at 5:43 am
> Objection. Relevance?
See masthead: “Commentary on puzzling things in … nature, science, ….”
Solar system formation is part of nature, and has been puzzled over by astronomers, who are scientists.
QED.
Mosh – thanks for posting this, I hadn’t heard the news.
Jim Cripwell – perhaps the swirling motion of the nascent solar system separates some of elements. maybe Leif could explain the mechanism. cheers.
“Relevance?”
Commentary on puzzling things in life, nature, science…
Jim, the without going too deeply into the Big Bang, and ignoring everything from Planks Era to the Era up to the end of the Era of Nucleosynthesis, the Universe was just a hot plasma cloud of mostly hydrogen and helium nuclei, with a bunch of free electrons and photons. The vast majority of the observable Universe is still comprised of hydrogen. If the Hubble Constant is accurate, the current estimated age of the Universe is 13.7 Gyrs, our Sun around 5 billion. There is an awful lot of hydrogen still not dense or hot enough to form into stars.
As for the other elements, I could start a thread on stellar formation and lives, but you could always look up what happens in high mass stars, how short their lives are, and what they produce when they die. Start here?
http://astronomyonline.org/Stars/HighMassEvolution.asp
“If this is how our solar system evolved, how can the sun be mainly hydrogen, and the planets have all the elements of the Periodic Table? Shades of Oliver Manuel.”
Because only large bodies such as a star or a gas giant have enough gravitational pull to collect significant quantities of hygrogen which is one of the lightest elements. The heavier elements precipitate into rocky bodies with very little hydrogen or helium in them. All of the heavier elements are created during supernova events from previous generations of stars.
I don’t know about relevence, but a very interesting post. Never ceases to amaze me, however, how no matter what branch of science we discuss, issues and processes which are highly speculative are pretty much presented as facts. Interesting is the real fact that every time we get a closer look at solar system objects we find out our “facts” were wrong!!! Reminds me of the climate issues presented here. Is it really too difficult to use the words, “possibly, maybe, we speculate, we theorize, a possible theory is that……”?
This disk eventually further consolidates to form planets, moons, asteroids and comets.
If this disk consolidates to form everything, why does it consolidate into multiple different things?
Thanks people for the comments. I still cannot see how a swirling mass that is mainly hydrogen, suddenly has elements like Uranium in it. The elements in the periodic table are thought to evolve in supernova. Hence Oliver Manuel’s idea that our sun was a supernova 5 billion years ago, and the solar system is the aggregation of the elements formed in the explosion, while the sun has a neutron star at it’s center, with the remainder being similar to what formed the planets. I still find this a much more plausible explanation.
Okay. Just to keep the “objectors” happy. How are they going to link this to Al Gorebull’s Weather?? Where’s the CO2 around the star’s “atmosphere” that’s making it so frickin hot??
It doesn’t explain (the protoplanetary disk) the halo of Kuiper Belt objects and the Oort cloud that are off the plane of the Solar System. Our own protoplanetary something-or-other might have formed in a SuperNova cloud remnant interacting with other clouds of galactic gas. There is too much Iron in the cores of the Planets.
Iron is the thermonuclear sink (think low energy wells of thermodynamics) for both fusion (of lower elements) and fission (of higher elements).
for preesolar elements see:
http://presolar.wustl.edu/work/grains.html
Tom_R says:
June 12, 2010 at 7:09 am
If this is how our solar system evolved, how can the sun be mainly hydrogen, and the planets have all the elements of the Periodic Table? Shades of Oliver Manuel.
The Sun also has all the elements. The separation comes about simply by temperature: the planets closer to the Sun are [were] to hot to retain Hydrogen and Helium, the Gas Giants have a large amount of H and He. No need for the neutron star etc. It is enough that there are plenty of supernovae scattered about. There has been about 1/4 billion supernovae in our Galaxy.
I still haven’t heard a good explanation of the nitrogen.
Nitrogen is common in the interstellar medium [from which the sun was formed – and whose heavier elements were formed in distant Supernovae]. But Nitrogen is chemically rather inert and so tend not to be taken up in rocks, hence left as atmosphere.
Jbar says: “Objection. Relevance?”
And your credentials that you imagine entitle you to object to a post here consist of…?