Planet and sun

[juvenissun]

Are planets formed before their sun?
Why not?

 

[AV1611VET]

Are planets formed before their sun?

You mean our planets? yes

Why not?

Good question.

An object being 'formed' ex nihilo is not synergistic; that is, it is not dependent on preexisting material, and so does not have to follow any kind of order.

 

[Agonaces of Susa]

Are planets formed before their sun?
Why not?

It depends on the particular circumstances of the star system.

In some cases, the planets are formed after the star or stars because giant gaseous protoplanets are ejected from stars at near orbits, first appearing as a bubble on the star's surface, as is currently the case with the pregnant red giant star Betelgeuse in the constellation Orion.

In other cases, the planets are formed before their star or stars as in some instances of planetary capture.

 

[Delphiki]

Because without a star to orbit, they wouldn't meet the definition of a planet. That's not to say that enough matter can't come together under the pull of gravity to make planet-sized objects before the center of the accretion disk starts a fusion process... But something like this has never been observed (as far as I'm aware of, anyway) because, well, there'd be no visible star to find it.

 

[Targ]

It depends on the particular circumstances of the star system.

In some cases, the planets are formed after the star or stars because giant gaseous protoplanets are ejected from stars at near orbits, first appearing as a bubble on the star's surface, as is currently the case with the pregnant red giant star Betelgeuse in the constellation Orion.

In other cases, the planets are formed before their star or stars as in some instances of planetary capture.

Agonaces, which came first: Earth or our former-star Saturn?

 

[Sphinx777]

The Sun...







​

 

[Agonaces of Susa]

Agonaces, which came first: Earth or our former-star Saturn?

Wonderful question; I don't know.

I think you'd have to ask God that question...

 

[Nabobalis]

Are planets formed before their sun?
Why not?

Both at a similar time. I hate to copy and paste but I'm late for a lecture.

Scientists believe that the solar system was formed when a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion made waves in space which squeezed the cloud of gas and dust. Squeezing made the cloud start to collapse, as gravity pulled the gas and dust together, forming a solar nebula. Just like a dancer that spins faster as she pulls in her arms, the cloud began to spin as it collapsed. Eventually, the cloud grew hotter and denser in the center, with a disk of gas and dust surrounding it that was hot in the center but cool at the edges. As the disk got thinner and thinner, particles began to stick together and form clumps. Some clumps got bigger, as particles and small clumps stuck to them, eventually forming planets or moons . Near the center of the cloud, where planets like Earth formed, only rocky material could stand the great heat. Icy matter settled in the outer regions of the disk along with rocky material, where the giant planets like Jupiter formed. As the cloud continued to fall in, the center eventually got so hot that it became a star, the Sun, and blew most of the gas and dust of the new solar system with a strong stellar wind. By studying meteorites, which are thought to be left over from this early phase of the solar system, scientists have found that the solar system is about 4,600 million years old!

 

[Wiccan_Child]

Planets form at roughly the same time as their host stars, though generally the star has to be active (i.e., undergoing fusion) to clear the intersystem debris and help the planets remain stable.

 

[juvenissun]

Planets form at roughly the same time as their host stars, though generally the star has to be active (i.e., undergoing fusion) to clear the intersystem debris and help the planets remain stable.

Eventually, the cloud grew hotter and denser in the center, with a disk of gas and dust surrounding it that was hot in the center but cool at the edges. As the disk got thinner and thinner, particles began to stick together and form clumps. Some clumps got bigger, as particles and small clumps stuck to them, eventually forming planets or moons .

So, the idea is still that the sun is activated first, then planets formed afterward. Even this is probably done in approximately the same time.

This is only an idea. Why should the star be activated first? And why couldn't the planet be condensed FIRST way before the majority of the gases condensed into the sun? Why should the planets start to form when the nebulous gases became thin enough? What is the support of of the alleged sequence according to physics?

I suggest the planets are made when the nebulous gases were still thick enough, which is way before the sun begin to take shape.

 

[Wiccan_Child]

So, the idea is still that the sun is activated first, then planets formed afterward. Even this is probably done in approximately the same time.

This is only an idea. Why should the star be activated first? And why couldn't the planet be condensed FIRST way before the majority of the gases condensed into the sun? Why should the planets start to form when the nebulous gases became thin enough? What is the support of of the alleged sequence according to physics?

Because of how the gas would have behaved. Initially, there were little to no indications of the future planets - just a large dust cloud collapsing under its own gravity. As things get hotter and older (i.e., long after the central proto-stars have taken form), it's only then that irregularities in the outerlying dust have begun to form their own miniature gravity wells.

In other words, the centre of the cloud will by default attract everything towards it - that's just gravity. It takes much longer, however, for clumps of dust to aggregate into anything approaching a planet. The Sun forms first because the centre of the cloud is already a gravitational well, while the future planets won't form until more gravitational wells form - and that takes time.

I suggest the planets are made when the nebulous gases were still thick enough, which is way before the sun begin to take shape.

Computer simulations beg to differ.

 

[juvenissun]

Because of how the gas would have behaved. Initially, there were little to no indications of the future planets - just a large dust cloud collapsing under its own gravity. As things get hotter and older (i.e., long after the central proto-stars have taken form), it's only then that irregularities in the outerlying dust have begun to form their own miniature gravity wells.

In other words, the centre of the cloud will by default attract everything towards it - that's just gravity. It takes much longer, however, for clumps of dust to aggregate into anything approaching a planet. The Sun forms first because the centre of the cloud is already a gravitational well, while the future planets won't form until more gravitational wells form - and that takes time.


Computer simulations beg to differ.

Could you provide one reference?

Why couldn't local gravity clumps formed in the early stage of nebula evolution? Look at a galaxy, the center of a galaxy is not as massive as a star to its planets.

 

[Nabobalis]

Could you provide one reference?

Why couldn't local gravity clumps formed in the early stage of nebula evolution? Look at a galaxy, the center of a galaxy is not as massive as a star to its planets.

If I recall when the star is formed, an accretion disk forms around the star and this starts transferring matter to the star (via angular momentum loss) and when the star becomes active it blows away the inner material and so the accretion disk is free to form planetoids (with is still an unknown process).

 

[Wiccan_Child]

Could you provide one reference?

Here's one.

Why couldn't local gravity clumps formed in the early stage of nebula evolution?

Any local clumps small enough to only form a planet would be swamped by the clumps large enough to form stars. It's only when the star has cleaned the surrounding area that planets can aggregate.

Look at a galaxy, the center of a galaxy is not as massive as a star to its planets.

Indeed: it's much, much heavier. Galactic cores are so very much heavier that they don't just form stars, they form a single supermassive black hole.

 

[Delphiki]

One reason why it's impossible for the planets to for first (that I didn't think about until now) is that the largest object in the dust cloud would have the most gravity, and therefore have the most influence on what the center of the planetary system would be, and also be the first thing in the cloud to become a star. So the planets can't form first, because the first and largest object formed out of the stellar dust would end up becoming the star anyway.

 

[jonmichael818]

Indeed: it's much, much heavier. Galactic cores are so very much heavier that they don't just form stars, they form a single supermassive black hole.

I wonder when and how we will be able to understand how dark matter is involved in the formation of galaxies.

 

[Delphiki]

I could be wrong here, but my understanding is that dark matter isn't some mysterious complicated mass we can't explain without a formula, but rather it's just all the stuff in the universe that doesn't emit it's own light.

 

[AV1611VET]

I could be wrong here, but my understanding is that dark matter isn't some mysterious complicated mass we can't explain without a formula, but rather it's just all the stuff in the universe that doesn't emit it's own light.

Interesting term (dark matter) -- it clears up a question I had pertaining to a passage:

2 Peter 2:4 For if God spared not the angels that sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved unto judgment;

 

[Agonaces of Susa]

I wonder if we can observe and test dark matter in the lab like we observe and test chains of darkness. If not, it seems dark matter is unscientific.

 

[Delphiki]

Explain how you test and observe these chains of darkness in hell?

Saying dark matter doesn't exist is kind of pointless anyway since the term, itself, is merely a placeholder for the small amount of mass that is unseen, but who's effects are seen keeping galaxies together and the universe from expanding quicker than it should according to what we actually see. Whether it's a bunch of dull rocky elements, some fifth fundamental force, or a flying spaghetti monster, the term for it is dark matter.

Our sun, for example, makes up 99.86% of the mass in the solar system. A distant observer would only see the sun, yet notice the tiny gravitational effect it has on other stars suggests that it should be slightly heavier than it appears... this missing .14% being the planets, asteroids, comets, oort cloud, etc -- the dark matter that can't be seen directly, but who's effects can be observed. Get it?