Baby Solar System Sprouts Mysterious Galaxy-Like Arms

A stunning photograph taken from the ALMA observatory in Chile shows a young star surrounded by a large disk of gas and dust. Like our very own Milky Way, this protoplanetary disk exhibits a spiral structure — a feature that could solve a lingering mystery about how planets start to form.

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CrazyNeutrino said:

Baby Solar System Sprouts Mysterious Galaxy-Like Arms

A stunning photograph taken from the ALMA observatory in Chile shows a young star surrounded by a large disk of gas and dust. Like our very own Milky Way, this protoplanetary disk exhibits a spiral structure — a feature that could solve a lingering mystery about how planets start to form.

more…

“this protoplanetary disk exhibits a spiral structure”

This was predicted back some time before the 1950s, perhaps even before the 1850s. But I thought it had been debunked. Aparrently not.

mollwollfumble said:

CrazyNeutrino said:

Baby Solar System Sprouts Mysterious Galaxy-Like Arms

A stunning photograph taken from the ALMA observatory in Chile shows a young star surrounded by a large disk of gas and dust. Like our very own Milky Way, this protoplanetary disk exhibits a spiral structure — a feature that could solve a lingering mystery about how planets start to form.

more…

“this protoplanetary disk exhibits a spiral structure”

This was predicted back some time before the 1950s, perhaps even before the 1850s. But I thought it had been debunked. Aparrently not.

“presence of these spiral arms comes as a relief to astronomers. Planets form in the disks of gas and dust around newborn stars, but it’s not clear how these tiny particles grow into objects as large as Saturn and Jupiter. When the protoplanetary disk is smooth and even, objects can only grow in a cumulative fashion as particles continually collide and clump together. The trouble is, when these bodies get a a metre or so across in width, the drag created by the surrounding gas makes them migrate towards the star. This process only takes about 1000 years, but larger timescales are required to build considerably bigger objects, and eventually planets.”

“Spiral arms could actually solve this conundrum. Their presence in the circumstellar disk — and the gravitational influence they exert — could disrupt the otherwise uniform composition of the disk. In regions with increased particle density, planet formation can move at a faster pace. The regions of uneven gravitational pull creates more confined space, making collisions of grains or rocks more likely.”

I’m in complete agreement here.

The presence of these arms in a circumstellar disk may help explain the formation of planets, but the next mystery to solve is the presence of the spirals themselves, and how they come to exist. A possible explanation is that a planet had already formed, but that presents a chicken-and-egg scenario. As the authors of the study themselves admit, more observations are needed.

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Does the sphere of gas condense down to a disk ?

in the disk depending on its density planets will form and create the spirals of matter

or do the planets and spirals form early when the cloud of gas condenses before the disk happens?

I think I’ll curry some left over roast beef tonight, with rice of course.
Bubblecar should be up soon, he might have some tips.

Peak Warming Man said:

I think I’ll curry some left over roast beef tonight, with rice of course.
Bubblecar should be up soon, he might have some tips.

Tip#1: try posting in the chat thread.

CrazyNeutrino said:

The presence of these arms in a circumstellar disk may help explain the formation of planets, but the next mystery to solve is the presence of the spirals themselves, and how they come to exist. A possible explanation is that a planet had already formed, but that presents a chicken-and-egg scenario. As the authors of the study themselves admit, more observations are needed.

> Does the sphere of gas condense down to a disk ?

Yes. Always. The spirals could be an intermediate semi-stable state shortly before the formation of the final disk

> in the disk depending on its density planets will form and create the spirals of matter

I haven’t ever seen the answer to that one. It would require some computer modelling,

> or do the planets and spirals form early when the cloud of gas condenses before the disk happens?

That’s what we hope.