What prevents the pressure from increasing too greatly in a molecular cloud as it contracts due to gravity thus allowing continued contraction and star formation?
Their low temperature keeps their pressures about the same as other interstellar clouds, despite the higher density. But the higher density means that gravity is stronger in molecular clouds, so it is able to overcome the pressure in molecular clouds.
What factors cause an interstellar cloud to resist contraction?
Gravity must overcome the interstellar magnetic field to make the gas contract. Since everything in the universe rotates, gas cloud begins to contract, it spins more and more rapidly as it conserves angular momentum. And this rotation can become so rapid that the cloud resists further contraction.
What does the gravitational force in a molecular cloud depend on?
The latter depends both on the density and temperature of the cloud. The high densities in molecular clouds means that the gravitational forces are relatively strong but the pressure is no higher than elsewhere because the temperatures are low.
Which kind of pressure prevents the formation of stars of extremely large mass?
The maximum mass is 150 solar masses. Radiation pressure limits the mass of a star. How do the numbers of low mass stars compare with those of high mass stars in new star clusters? Observations of newly formed populations of stars have shown us that very few high mass stars form, while many low mass stars form.
Which trigger could start the gravitational contraction of a molecular cloud?
In triggered star formation, one of several events might occur to compress a molecular cloud and initiate its gravitational collapse. Molecular clouds may collide with each other, or a nearby supernova explosion can be a trigger, sending shocked matter into the cloud at very high speeds.
How does the contraction of a gas cloud increase its temperature?
How does the contraction of a gas cloud increase its temperature? Collisions convert the inward velocities of the atoms into random motions, thus the temperature of the gas goes up. Conversion of potential gravitational energy to thermal energy.
Which factors resist the collapse of a cloud?
Cards
| 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 |
•Apr 1, 2009
Which factor resists the contraction of a cloud of interstellar matter quizlet?
The gravitational force. Which factor resists the contraction of a cloud of interstellar matter? (Thermal energy.
What slows down the contraction of a star-forming cloud when it makes a protostar?
Conclusion: Hence, trapping of thermal energy inside the protostar slows down the contraction of a star-forming cloud when it makes a protostar.
What triggers the gravitational collapse of material inside a molecular cloud?
What triggers the gravitational collapse of material inside a molecular cloud? A passing shock wave. What eventually halts the slow contraction of a newly forming star? Nuclear fusion.
Why doesn’t gravity immediately cause the collapse of all interstellar clouds?
Heat pressure: If interstellar gas is warm enough, this pressure will prevent gravity from causing fragmentation and collapse. This accounts for the fact that we see star formation occurring only in the very cold dense clouds, never in the relatively warm diffuse interstellar gas.
What can interfere with gravitational collapse while a star is forming?
Star formation happens when part of a dust cloud begins to contract under its own gravitational force; as it collapses, the center becomes hotter and hotter until nuclear fusion begins in the core. Rotation can also interfere with gravitational collapse, as can magnetism.
What eventually halts the gravitational collapse of an interstellar gas cloud that forms a brown dwarf rather than a true main sequence star?
Which of the following must be occurring in order for a molecular cloud to collapse and form stars? The buildup of thermal energy in a collapsing gas cloud leads to thermal pressure that can halt the gravitational collapse.
What happens to the cloud as gravity pulls the cloud together?
Gravity, which causes all the atoms of the gas to pull each other together, makes the cloud contract. As the cloud gets smaller, the atoms of the gas get closer together and begin to bump into each other more, which heats them up.
Which trigger could start the gravitational contraction of a molecular cloud quizlet?
Which trigger could start the gravitational contraction of a molecular cloud? Low-mass stars like the Sun transport energy near their surface using convection. The ISM magnetic field is typically about 0.0001 times as strong as Earth's magnetic field at its surface.
What stops a neutron star from collapsing further under the influence of gravity?
This is called Electron degeneracy pressure and prevents gravity collapses. In Neutron stars, the stars are too massive for this principle, instead the electrons are captured by protons and make into neutrons and release neutrinos which create pressure that prevent the star from collapsing due to gravity.
What prevents stars from collapsing?
Stars are fueled by the nuclear fusion of hydrogen to form helium deep in their interiors. The outflow of energy from the central regions of the star provides the pressure necessary to keep the star from collapsing under its own weight, and the energy by which it shines.
What is gravitational contraction?
Gravitational contraction. The process in which gravity causes an object to contract, thereby converting gravitational potential energy into thermal energy. Gravitational equilibrium. A state of balance in which the force of gravity pulling inward is precisely counteracted by pressure pushing outward.
What kind of pressure prevents brown dwarfs from beginning core fusion?
However, brown dwarfs prevent further contraction because their cores are dense enough to hold themselves up with electron degeneracy pressure. (Those brown dwarfs above 60 Jupiter masses begin to fuse hydrogen, but they then stabilize, and the fusion stops.)
Which force is most responsible for the contraction of gas cloud?
Gravity, which causes all the atoms of the gas to pull each other together, makes the cloud contract.
How do low mass stars in the lower region of the main sequence produce their energy?
In the lower main sequence, energy is primarily generated as the result of the proton–proton chain, which directly fuses hydrogen together in a series of stages to produce helium.
Where does hydrostatic equilibrium exist in the Sun?
Hydrostatic equilibrium is the state where the force of gravity pulling inward is balanced by pressure pushing outward. In the core of the Sun, hydrogen is being fused into helium via nuclear fusion. This creates a large amount of energy flowing from the core which effectively creates an outwardpushing pressure.
What kind of pressure prevents a white dwarf from collapsing quizlet?
Degeneracy pressure keeps a white dwarf from collapsing under its own gravity.
What prevents a neutron star from collapsing and becoming a black hole?
What prevents a neutron star from collapsing and becoming a black hole? Gravity in the neutron star is balanced by an outward force due to neutron degeneracy. about 3 solar masses. no light can escape from it due to its powerful gravitational field.
What prevents gravitational collapse?
Star formation Mathematically this is expressed using the virial theorem, which states that, to maintain equilibrium, the gravitational potential energy must equal twice the internal thermal energy.
What keeps the Earth from collapsing under its own gravity?
In the case of the Earth, the weight is supported by the resistance to compression provided by the materials (solids and liquids) that make up the Earth: the pressure is sufficient to compress these materials a little, but the atoms that compose them repel one another and prevent collapse.
What stops gravitational contraction?
The compression caused by the collapse raises the temperature until thermonuclear fusion occurs at the center of the star, at which point the collapse gradually comes to a halt as the outward thermal pressure balances the gravitational forces.
What force prevents a main sequence star from collapsing?
Stars on the main sequence are those that are fusing hydrogen into helium in their cores. The radiation and heat from this reaction keep the force of gravity from collapsing the star during this phase of the star's life.
What keeps a white dwarf from collapsing due to gravity?
In particular, electron degeneracy pressure is what supports white dwarfs against gravitational collapse, and the Chandrasekhar limit (the maximum mass a white dwarf can attain) arises naturally due to the physics of electron degeneracy.
What type of pressure halts the collapse of a brown dwarf?
An object too small to become an ordinary star because electron degeneracy pressure halts its gravitational collapse before fusion becomes self-sustaining; brown dwarfs have mass less than 0.08MSun.