Questions tagged [star-formation]

Questions related to the physical processes involved in or to the observations of the process of forming a star.

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Does the Sun rotate?

The planets rotate as an after effect of their creation, the dust clouds that compressed span as they did so and the inertia has kept it rotating ever since. It's fairly easy to prove that planetary ...
user avatar
42 votes
2 answers
4k views

Are new stars less pure as generations go by?

If stars are primarily made of hydrogen, which is then burned to helium, and then on and on and on down the chain until you either reach iron, or in extreme cases much heavier metals, this then ...
Electric Coffee's user avatar
38 votes
2 answers
7k views

Why are the Pillars of Creation pillar-shaped?

The Pillars of Creation have a strong directional sense. They are referred to as "pillars" and another question asks how "tall" they are. Naively, it looks as if there is a source ...
Mark Foskey's user avatar
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32 votes
1 answer
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If two white dwarfs collided, would they become a star?

Would the temperatures during such a collision be able to ignite nuclear fusion, bringing the dead star back to life? If so, would it only be able to fuse for a short time before running out of fuel, ...
Gliese's user avatar
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24 votes
3 answers
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Did the Sun's light always peak in the green wavelengths?

So, I know the sun is getting brighter over it's lifespan and I'm wondering how that affects its emission spectrum. The reason I'm asking this is because I find it weird that plants reflect green ...
Elhammo's user avatar
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20 votes
2 answers
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Will new stars stop forming at some point of time?

New stars keep forming in the universe thanks to all the nebulae. Now, we need Hydrogen to form stars and there would a time when all the hydrogen will get exhausted, and no more star formation will ...
Ranveer's user avatar
  • 539
19 votes
2 answers
2k views

Which stars did the Sun form with?

The Sun formed 4.5 billion years ago, in a molecular cloud. I assume that there were other stars in the vicinity (as is common in molecular clouds). Which stars are they? Where are they now? Are they ...
HDE 226868's user avatar
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18 votes
1 answer
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How can a brown dwarf be more massive than a star?

SDSS J0104+1535 is about 90 times more massive than Jupiter, making it the heaviest known brown dwarf. EBLM J0555-57Ab has a mass of about 85.2±4 Jupiter masses, or 0.081 Solar masses. I am confused. ...
Binita Rimal's user avatar
17 votes
2 answers
4k views

Could stars form outside of galaxies?

Is it possible for there to be a dense enough nebula to form stars outside of any galaxy? Does a galaxy have a minimum size to produce stars? Or could you have a few dozen stars clustered together by ...
Lorry Laurence mcLarry's user avatar
16 votes
1 answer
3k views

How are we observing the newly discovered "dark galaxy" J0613+52, if it has no stars and is so far away from other galaxies?

I just came across a New York Times article talking about a newly found Low Surface Brightness (LSB) galaxy (also called “ultra-diffuse galaxies” or “dark galaxies”). The new galaxy, J0613+52, was ...
Curious Layman's user avatar
16 votes
2 answers
843 views

Characteristics of the first planets in the Universe?

What would have the very first planets looked like, based on their most likely chemical compositions? For example: Were they mostly grey gas giants with atmospheres of hydrogen and helium, ...
Dave Jarvis's user avatar
15 votes
1 answer
208 views

Mechanisms of binary/multiple star formation

What are mechanisms of binary/multiple star formation in different mass ranges (low, intermediate and high stellar masses)?
user2579566's user avatar
14 votes
2 answers
4k views

How can many stars be formed from the remains of one supernova?

A supernova is the explosion of a single star; so how is it that thousands of stars can "be born of" that one explosion (presumably only using the unspent fuel / lighter elements of the ...
Still.Tony's user avatar
14 votes
2 answers
3k views

How did the lighter elements end up in the center of the solar system? Solar System Formation

The previous generation of stars famously are the origin of all the heavier elements (up until iron?) in the solar system. So a big portion of the solar system mass actually is made up of Carbon, ...
lthz's user avatar
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14 votes
2 answers
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How are binary star systems created?

I don't know how common it is for a system to have two stars (or perhaps even more) but how do they arise? Is that due to the stellar accretion disc, or the composition of the stellar nebula? Or are ...
Marijn 's user avatar
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13 votes
1 answer
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Can stars form in the stellar halo?

The wiki page for Galactic Halo states: Star formation in the stellar halo of the Milky Way ceased long ago. In addition, the wiki page for Stellar Halo states: Astrophysical simulations of ...
Shawn Lim's user avatar
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12 votes
2 answers
392 views

Can protoplanetary disks form main-sequence stars?

As has been pointed out by @Envite in the context of a more general discussion (see Generalised planets?), there seems to be a moderate possibility for protoplanetary discs forming main-sequence stars ...
Alexey Bobrick's user avatar
12 votes
1 answer
1k views

Why does a hot cloud need more mass to collapse?

I was wondering why does a hot cloud need more mass to collapse than a cold cloud to form a protostar? Is it because there's a higher thermal pressure inside the hotter cloud than it is in a colder ...
space nerd's user avatar
12 votes
2 answers
1k views

Why aren't there blue elliptical galaxies or yellow spiral galaxies?

Elliptical galaxies are universally old and yellow; about three-quarters of all ellipticals have no significant star-forming gas or dust left, and even the quarter or so of ellipticals that are still ...
Vikki's user avatar
  • 625
12 votes
2 answers
398 views

What will future populations of stars be like?

As stars slowly using up hydrogen and ejecting heavier elements into space, the future stars will form from nebulae that are more metal and helium rich. The question is: how does the increased ratio ...
Calmarius's user avatar
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11 votes
0 answers
210 views

What is the birth of a star like? [closed]

Here's what I'm curious about. So this hydrogen gas collects and at some point, it eventually becomes a star. What does that process look like? If you were there as a witness to the formation of a ...
Pete's user avatar
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10 votes
3 answers
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Can stars be born giants?

My understanding is that giant stars are formed when they leave the main sequence and begin to burn elements heavier than hydrogen. Can some stars, however, be born as giants or do all stars start off ...
Andykins 's user avatar
10 votes
2 answers
193 views

Star formation around rotating black holes?

Please excuse an amateur question. While trying to think of anything but what was happening during a dental procedure my mind turned to a model of a star close to a rotating black hole and the ...
FlipC's user avatar
  • 103
10 votes
3 answers
810 views

Why is the composition of the sun so distinct from that of earth?

Given that the sun is – in astronomical distances – quite close to the earth, why are the two composed of such distinctly different substances? Sun Composition Hydrogen 74.9% Helium 23.8% Oxygen ~1% ...
Cory Klein's user avatar
9 votes
1 answer
1k views

Star formation - Is it just gas accumulation or does dust also play a role?

Inspired by the question, Are heavy elements equally distributed throughout the Solar System?, with a little further inspiration from this one as well, Star formation analogy, particularly the answer ...
Fred's user avatar
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9 votes
2 answers
7k views

Which came first: Galaxies <=> Stars <=> Planets?

If a galaxy is defined as a collection of planetary systems (and all matter in between), and a planetary system is defined as a collection of planets circling a star (and all matter in between), and a ...
EveryBitHelps's user avatar
9 votes
1 answer
852 views

What is the origin of the dust near the sun?

note: Solar Probe+ is now officially Parker Solar Probe In How can the Parker Solar Probe survive passing within 4 million miles of the sun's surface? I asked about the Solar Probe Plus mission. ...
uhoh's user avatar
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8 votes
1 answer
1k views

Why can't 'dead' galaxies start forming stars again if they merge with another, 'active' galaxy?

I heard Matthew O'Dowd mention on PBS Space-Time that dead galaxies cannot start re-forming stars even if they collect gas and/or dust from elsewhere, or even merge with another galaxy.... Why? And ...
Kurt Hikes's user avatar
  • 5,077
8 votes
1 answer
656 views

How much matter was ejected when the Solar System formed?

Assuming the accretion disk model for the formation of the Solar System, the most important problem, according to wikipedia, is "how the material, which is accreted by the protostar, loses its ...
Connor Garcia's user avatar
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8 votes
2 answers
889 views

What causes jets from newly born stars?

Newly born stars often have bilateral jets of gas ejected from them at high speeds (hundreds of km per seconds), often ending in Herbig-Haro objects. As I understand it those jets would have something ...
stevenvh's user avatar
  • 803
8 votes
2 answers
301 views

Can dark matter decrease the Jeans length?

I am wondering if there are any models of interstellar cloud collapse out there which take dark matter into account. If dark matter has local perturbations or density fluctuations, then that may be ...
dualredlaugh's user avatar
7 votes
2 answers
1k views

What kind of nebula was the Sun formed from?

I was just wondering what type of nebula did the Sun form from because mainly there are 5 categories: emission nebulae, reflection nebulae, dark nebulae, planetary nebulae, and supernova remnants, so ...
user avatar
7 votes
2 answers
1k views

Is there a (proposed) name for Coatlicue's progenitor?

Our sun's theorized progenitor star carries the (proposed) name Coatlicue. Since our sun is thought to be a third generation* star there should be two generations preceding it - and therefore one ...
nada's user avatar
  • 216
7 votes
1 answer
2k views

Mechanism for Brown Dwarf Fusion

I've read (at here, among other places) that during the Degenerate Era, star formation will end and the last stars will go out. But it was noted that there is still the possibility of star birth, ...
HDE 226868's user avatar
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7 votes
2 answers
959 views

How were the first stars formed?

In class, we read a Scientific American article, "Cloudy with a Chance of Stars" that explained how the cores and the dust around them formed stars(he called them eggs for a chicken/egg analogy, where ...
rcteg's user avatar
  • 71
6 votes
4 answers
696 views

Can a donut-shape planet or star be formed?

How stable is a donut-shaped star or planet configuration and under what conditions such object may form? Is there any evidence suggesting that such objects might exist?
user3715778's user avatar
6 votes
1 answer
152 views

How many generations of stars can be formed in the Stelliferous Era?

As in general case, stars are formed from nebula which in some case itself is the result of a supernova. Also stars need hydrogen to become a star (to do nuclear fusion), but stars consume hydrogen in ...
aDEp's user avatar
  • 61
6 votes
1 answer
105 views

Activity of M dwarf stars

Why are M dwarf stars the most active (in terms of starspots and faculae) of all stars?
user4437416's user avatar
6 votes
2 answers
2k views

What does the ']' in the spectral line "CIII] 1909 Å" mean?

The above emission line, as I understand, is a useful probe of early star-forming galaxies. However, I do not understand what the ']' to the right of the 'CIII' means. I could not find any online ...
H3007's user avatar
  • 63
6 votes
2 answers
279 views

The formation of new stars as depicted in Feynman's lectures

I've stumbled upon this curious passage addressing the formation of stars in Feynman's lectures on physics: Whether we have ever seen a star form or not is still debatable. Figure 7–12 shows the ...
Vlas Sokolov's user avatar
6 votes
1 answer
205 views

How much of a molecular cloud can end up as "starstuff"?

Stars form within molecular clouds. These clouds can be up to 6 millions solar masses. When the cloud collapses into stars, is it possible to know a rough figure for how much of this material actually ...
usernumber's user avatar
  • 17.5k
6 votes
1 answer
310 views

Formation of the First Stars

I've got a few questions about the first stars to form in the universe. First off how might metalicity have impacted the formation of the first stars and also what effect would the absence of metals ...
PSR-1937-21's user avatar
6 votes
0 answers
45 views

Are metallicities of molecular clouds lower in the outskirts of the galaxy?

(this question was originally posted in an answer by user PSR-1937-21 to another post. I find it an interesting one, but since they don't seem to be active anymore, I'm posting it to see if somebody ...
SE - stop firing the good guys's user avatar
5 votes
2 answers
3k views

The star that created our sun

Is the location of the star that would have created our sun known? Meaning our sun's parent star which would have provided the material when it died? If not, has there been any theories on what kind ...
eBookworm's user avatar
  • 145
5 votes
3 answers
984 views

Is it possible for a star cluster to be composed of main sequence stars?

From what I hear about globular clusters, they are primarily composed of very hot giant stars, which are not the most conducive for life as we know it. Main sequence stars like our own, due to their ...
user98816's user avatar
  • 469
5 votes
2 answers
1k views

Could a quasi-neutron-star exist between the maximum mass of a star and the mass of a quasi-star?

A quasi-star is a hypothetical supermassive star that is so heavy its core collapses into a black hole as it is still forming. The matter accreting into the black hole then generates radiation ...
Hene's user avatar
  • 255
5 votes
1 answer
342 views

Black Dwarf Capabilities

Can a black dwarf be suitable for manned exploration, once it cools down? And potentially used for space mining?
Jay's user avatar
  • 153
5 votes
1 answer
161 views

How long will star formation endure before the eventual heat death of the observable universe?

Lord Kelvin's prediction of heat death indicates the eventual end to star formation in the observable universe. Have any astrophysicists made any predictions for the endurance of star formation in the ...
James Goetz's user avatar
5 votes
1 answer
2k views

Where do new stars get their hydrogen from? [duplicate]

When stars run out of hydrogen, they explode (though they also use heavier elements for some time) and form nebulae. In the nebulae, new stars are born which use hydrogen as their fuel. So, my ...
another 'Homo sapien''s user avatar
5 votes
1 answer
116 views

Galactic orbits and distance between stars

In the context of whether or not nearby stars were created from the same nebula, this answer states: imagine two stars with very similar orbits, one with a period of 200 million years and the other ...
RonJohn's user avatar
  • 409