Summary: Stars form in cold, dense regions of space called molecular clouds. When the force of gravity pulling in on the cloud is greater than the strength of internal pressure pushing out , the cloud collapses into a protostar.
What would not trigger the collapse of a molecular cloud?
The formation of stars occurs exclusively within molecular clouds. This is a natural consequence of their low temperatures and high densities, because the gravitational force acting to collapse the cloud must exceed the internal pressures that are acting “outward” to prevent a collapse.
What are some of the reasons that a giant molecular cloud GMC will begin collapsing?
- Cloud-Cloud collisions.
- Shocks from nearby supernova explosions.
- Passage through a spiral arm of the Galaxy.
What physical process causes a Protostellar cloud to collapse into a disk?
The formation of a protostellar disc is a natural outcome during the star formation process . As gas in a molecular cloud core collapses under self-gravity, the angular momentum of the gas will slow its collapse on small scales and promote the formation of a protostellar disc.
What happens when a molecular cloud collapses?
A cloud may start with any size or shape, and different clumps of gas within the cloud may be moving in random directions at random speeds. When the cloud collapses, these different clumps collide and merge, resulting in a flattened rotating disk .
What are some viable causes of a molecular cloud to begin collapsing quizlet?
A shock wave will cause the molecular cloud to collapse. The shock wave could either be from a violent event, like a supernova, or the stellar winds from young stars compressing the gas around them. What is the source of energy in a protostar? into thermal energy as the gas and dust falls toward the protostar.
What is necessary for a molecular cloud to collapse quizlet?
When a huge molecular cloud starts to collapse, gravity pulls the gas toward the cloud’s densest regions , which causes it to break into smaller pieces that each form one or more stars which is a protostar. ... A disk forms because collisions between gas particles cause the cloud breakage to flatten along it rotation axis.
What stars form the slowest?
What stars form the slowest? infrared spectrum .
What will happen if the cloud does not have enough mass?
What will happen if the cloud does not have enough mass? ... A protostar forms as mass increases . Nuclear fusion begins under high pressure. A protostar collapses and becomes denser.
What causes a nebula gas cloud to collapse?
Irregularities in the density of the gas causes a net gravitational force that pulls the gas molecules closer together. Some astronomers think that a gravitational or magnetic disturbance causes the nebula to collapse. As the gases collect, they lose potential energy, which results in an increase in temperature.
What makes a cloud to spin faster?
All clouds rotate, at least a little, due to gravitational shearing in the galaxy’s disk. And if a cloud rotates, it has angular momentum : L ~ mrv. And remember that angular momentum is conserved. So if a rotating cloud collapses (r gets smaller) than it must spin faster (v gets bigger).
What supports the Sun against gravitational collapse?
The atoms in the central regions move faster than those in outer regions and consequently they push outwards with more force, holding the Sun up. The force which they exert is described by the pressure; the internal pressure is higher than the external pressure, so the Sun is held up against gravitational collapse.
What happens to the angular momentum of a collapsing cloud as it turns into a star?
The concept of angular momentum predicts what happens to the rotation as the cloud collapses. ... As a star forming cloud begins to contract, the rotation rate must increase , because angular momentum is conserved. In general, a big, slowly rotating system will turn into a small, rapidly rotating system.
What is the mass at which a molecular cloud will collapse?
| Diffuse HI Cloud Molecular Cloud Core | Temperature 50 K 150 K | Density 500 cm – 3 10 8 cm – 3 | Mass 1-100 M sun 10-1000 M sun |
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What are the 2 reasons molecular clouds are the perfect place for star formation?
Molecular clouds are favorable locations for star formation for two reasons: low temperature and high density . Their low temperature keeps their pressures about the same as other interstellar clouds, despite the higher density.
Which factors resist the collapse of a cloud?
| Term What does star formation generally occur from? Definition the cores of giant molecular clouds | Term What are the four factors that resist the collapse of a cloud? Definition 1. thermal energy (pressure) 2. magnetic fields 3. rotation 4. turbulance | Term What is another word for rotation? Definition angular momentum |
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