Exploring the Formation of Stars: Myths vs. Reality

  • Thread starter superweirdo
  • Start date
  • Tags
    Stars
In summary, stars are formed from dust and hydrogen in Nebulae through the process of gravity creating lumps that increase in size and heat up. When they reach a certain temperature, they begin fission of hydrogen, also known as fusion. Black holes are not the only source of star formation, as they can also be triggered by powerful high-speed jets from black holes. Only very massive stars have the potential to become black holes, while most stars become white dwarfs or are ripped apart in a supernova explosion. Supermassive black holes, which exist in the center of galaxies, may be of primordial origin or formed from existing black holes that have absorbed a large amount of matter. The exact limit for a
  • #1
superweirdo
156
0
Someone told me stars are formed by black hole, yet, I didn't believe him, are they really?
 
Astronomy news on Phys.org
  • #2
no

look up star birth

its from dust + hydrogen in Nebulae + gravity makes lumps which get bigger and bigger causeing the dust to heat up

when they heat up enought they start fission of hydrogen
 
  • #3
You might get more conversation in the astrophysics forum
https://www.physicsforums.com/forumdisplay.php?f=2 [Broken]
 
Last edited by a moderator:
  • #5
star.torturer said:
when they heat up enought they start fission of hydrogen

You mean... fusion.

- Warren
 
  • #6
Yep I do Warren, thanks for pointing this out.
I also knew that it was Fusion, but I didnt proof read the post, Sorry!
 
  • #8
thats interesting, i fully understand where hees coming from. looks like he was kinda right after all
 
  • #9
superweirdo said:
Check this link out, that how he proved it to me.
http://www.space.com/scienceastronomy/mystery_monday_050207.html

Well that isn't the role of a black hole everybody assumed your original post was referring to. Here's a quaote from the site.

New observations portray black holes as Jekyll and Hyde characters. They can be creators as well as destroyers.

The classic view of black holes conjures images of gas and stars and even light being swallowed. That's why they're black. But when black holes feed, they create powerful high-speed jets that race at nearly light-speed into surrounding space.

Like a jolt of electricity breathing life into Frankenstein's monster, a black hole's jets can ignite star formation.

Wil van Breugel and Steve Croft of the Lawrence Livermore National Laboratory studied one of these jets slicing through a puzzling region of intense star formation known as Minkowski's Object. The jet, they say, caused a dense gas cloud to collapse and trigger the star birth.

So the star formation process currently supposed - condensation from a cloud - isn't being challenged. Rather it's proposed that a jet from a black hole triggers that process, at least in some cases.
 
  • #10
But since everytime stars die, they turn into black hole and black hole gives off the stuff needed to make the stars, doesn't it make most of the stars?
 
  • #11
superweirdo said:
But since everytime stars die, they turn into black hole and black hole gives off the stuff needed to make the stars, doesn't it make most of the stars?
Please start at http://www.astronomynotes.com/evolutn/s2.htm" [Broken] for a decent answer to your questions so far. After reviewing that, you might have some more specific questions.(?) That website has nice pictures too...
 
Last edited by a moderator:
  • #12
superweirdo said:
But since everytime stars die, they turn into black hole and black hole gives off the stuff needed to make the stars, doesn't it make most of the stars?

Not all stars evolve into black holes. And black holes don't give off anything but radiation in the form of x-rays...
 
  • #13
Only very massive stars (more than twenty-five times the mass of the Sun) have the potential to become black holes when they die. Most stars do not become black holes, becoming instead only white dwaf stars or being ripped to shreds in a supernova explosion.

- Warren
 
  • #14
chroot said:
Only very massive stars (more than twenty-five times the mass of the Sun) have the potential to become black holes when they die. Most stars do not become black holes, becoming instead only white dwaf stars or being ripped to shreds in a supernova explosion.

Well, not entirely ripped to shreds. We expect intermediate mass stars (3 solar masses) to leave behind neutron stars when they die.
 
  • #15
Wait a sec., supermassive stars become normal black hole then what kind of stars make up supermassive black hole. I thought that whenever a star dies, it becomes a black hole and the bigger a star is, the bigger the balck hole is.
 
  • #16
'supermassive black holes' 'exist' in he center of Galaxies, where a collosal mass must have existed to pull together the stars in a galaxy.
 
  • #17
But normal black holes are formed by normal stars right? And supermassive black hole are formed by supermassive stars.
 
  • #18
normal black holes are formed by masive stars

supermassive black holes are formed at the creation of a Galaxy, or maybe a colision of multiple massive stars
 
  • #19
Supermassive black holes may be of primordial origin, born long before the universe cooled enough to to allow stars to form. On the other hand, they could be simply normal black holes that have absorbed a large amount of matter after formation. The supermassive black holes suspected to exist at the centers of galaxies are almost certainly of primordial origin, and served as the "attractors" that pulled galaxies together in the early universe.

Perhaps one of our resident astronomers can expand more on the topic?

- Warren
 
  • #20
superweirdo said:
Wait a sec., supermassive stars become normal black hole then what kind of stars make up supermassive black hole. I thought that whenever a star dies, it becomes a black hole and the bigger a star is, the bigger the balck hole is.


No, only stars with a enough mass so that gravity overcomes the neutron degeneracy pressure will become black holes. We're not entirely sure what that limit is though, because accurately determining the neutron degeneracy pressure is much harder than say determining the electron degeneracy pressure (which is what keeps white dwarfs from collapsing). Its likely that you can't have a neutron star much larger than 3 solar masses (the star that formed the neutron star would of course be much larger). Supermassive black holes would be formed by matter falling into an existing black hole, cause into to grow. You can't have stars much over 100 solar masses as they slimply blast matter off with radiation driven stellar winds when they get to be that big.
 
  • #21
chroot said:
Supermassive black holes may be of primordial origin, born long before the universe cooled enough to to allow stars to form. On the other hand, they could be simply normal black holes that have absorbed a large amount of matter after formation. The supermassive black holes suspected to exist at the centers of galaxies are almost certainly of primordial origin, and served as the "attractors" that pulled galaxies together in the early universe.

Perhaps one of our resident astronomers can expand more on the topic?

- Warren
It is generally thought that making primordial SMBHs is difficult to explain and those that do exist may have formed by multiple mergers.

Maybe from a swarm of BHs?

Garth
 
  • #22
Supermassive black holes may be of primordial origin, born long before the universe cooled enough to to allow stars to form. On the other hand, they could be simply normal black holes that have absorbed a large amount of matter after formation. The supermassive black holes suspected to exist at the centers of galaxies are almost certainly of primordial origin, and served as the "attractors" that pulled galaxies together in the early universe.

Some think black holes could have formed in the early universe, perhaps during a phase transition. This "primordial black hole" hypothesis is actually pretty fringe (though not crank). It is possible that such objects acted as the seeds for supermassive black holes, but most think that SMBHs were seeded by the remnants of Population III (metal-free) stars.

As for the SMBH role in galaxy formation, they may have helped shape the bulges of spiral galaxies (we see correlations between black hole properties and bulge properties), but the primary seeds of galaxy formation were almost certainly the fluctuations put in place by inflation. I suspect that the radiative and kinetic output of AGN (accreting SMBHs) would have been more important in shaping galaxies than the graviational influence of the black holes themselves.
 

1. What are some common misconceptions about the formation of stars?

Many people believe that stars are formed from the remnants of supernovae, but in reality, this only accounts for a small percentage of star formation. Another common myth is that stars are formed from the collision of galaxies, when in fact, stars are formed within galaxies through the collapse of gas and dust clouds.

2. How do stars actually form?

Stars form through the process of gravitational collapse. A large cloud of gas and dust contracts due to its own gravity, causing the temperature and pressure at the center to increase. This triggers nuclear fusion, and a new star is born.

3. What role do protoplanetary disks play in star formation?

Protoplanetary disks are flat, rotating disks of gas and dust that surround young stars. They play a crucial role in the formation of planets, as the dust particles within the disk clump together to form larger bodies, eventually leading to the formation of planets.

4. How long does it take for a star to form?

The time it takes for a star to form varies depending on its mass. Low-mass stars, like our sun, can take several million years to form, while high-mass stars can form in just a few hundred thousand years.

5. Can stars continue to form after their initial creation?

Yes, stars can continue to form throughout their lifetime. This is known as "stellar recycling" and occurs when older stars shed their outer layers, which then mix with gas and dust in the interstellar medium, eventually forming new stars.

Similar threads

Replies
6
Views
842
  • Astronomy and Astrophysics
2
Replies
48
Views
685
  • Astronomy and Astrophysics
Replies
18
Views
1K
  • Astronomy and Astrophysics
Replies
5
Views
1K
  • Astronomy and Astrophysics
Replies
5
Views
1K
  • Astronomy and Astrophysics
2
Replies
53
Views
5K
Replies
14
Views
1K
  • Astronomy and Astrophysics
Replies
2
Views
705
Replies
4
Views
2K
Back
Top