Why is there an upper mass limit for main sequence stars about 100 to 150 solar masses group of answer choices?

Main sequence stars have an upper mass limit of about 100 to 150 solar masses due to an interplay between two of the star’s processes: stellar winds and radiation pressure. Stellar winds are caused by the high temperatures and pressures of a star’s core, which causes it to emit charged particles, like electrons and protons, that travel away from the star until they escape its gravitational pull.

This creates a steady outflow of material, called the stellar wind. The strength of the stellar wind increases with the star’s mass, and can affect the star’s atmosphere by dispersing and cooling it.

Radiation pressure is the pressure created by the star’s radiation, primarily in the form of visible light and ultraviolet light. Radiation pressure is created when photons escape the star’s surface and interact with the surrounding material in the star’s atmosphere.

Both stellar winds and radiation pressure are caused by the star’s internal energy, so the stronger the energy output, the stronger the effect of stellar winds and radiation pressure.

The importance of stellar winds and radiation pressure on main sequence stars brings us to why there is an upper limit to the mass of main sequence stars. At a certain mass, the strength of the stellar wind and radiation pressure causes the star to begin ejecting material at an accelerating rate.

This process is known as mass-loss or supernova mediated mass-loss. Material is ejected at such a high rate that it overpowers the star’s gravity, and it is then dispersed into space. As a result, the star never reaches the mass necessary to initiate fusion and become a giant star.

This means that main sequence stars are limited in size and can never exceed around 100 to 150 solar masses.

Why is there a lower mass limit of .08 solar masses for main sequence stars?

The lower mass limit of. 08 solar masses for main sequence stars is determined by the nuclear fusion process in their cores. While stars of all masses may form, stars below this mass are not capable of sustaining the core temperatures and pressures necessary to undergo fusion efficiently.

Therefore, once the fuel in their core is depleted, they eventually fade away quickly and do not survive to become red dwarfs or any other type of main sequence star. This is why stars with masses below this lower limit are known as brown dwarfs, or failed stars.

Why are there so few upper main sequence stars Why are there so many lower main sequence stars?

The main reason why there are fewer upper main sequence stars is because they are much more massive than lower main sequence stars. This means that they burn through their fuel more quickly and therefore, have a much shorter lifespan.

Upper main sequence stars usually produce copious amounts of radiation and other high-energy emissions which cause them to age quickly. As they age, they move up the main sequence, eventually becoming hotter and brighter until they eventually transform into white dwarfs.

In comparison, lower main sequence stars are much less massive and, therefore, have much longer lifespans. They also produce less radiation, so they age much more slowly. As a result, they remain on the main sequence for a much longer period of time, allowing them to greatly outnumber the population of upper main sequence stars.

Why don’t we find stars more massive than about 100 times the mass of the sun?

Stars have a theoretical upper limit of mass known as the Eddington Limit. To maintain balance between radiation pressure and gravity, the mass of any star cannot exceed the Eddington Limit, which is approximately 100 times the mass of the sun.

Anything past this point would be susceptible to extreme instability and turbulent radiation pressure, which could cause the star to explode before its reach its full stage of being a supergiant. This is why, to date, we haven’t been able to observe stars bigger than 100 times the mass of the sun.

What is the upper limit for a star’s mass What is the lower limit?

The upper limit for a star’s mass is believed to be around 150 solar masses, although there is some debate about the precise upper limit. There are some theories that propose that there is no real upper limit, but this has yet to be proven.

The lower limit for the mass of a star is believed to be around 0. 08 solar masses. Stars that have a mass below this point are not able to sustain nuclear fusion, falling into the category of a failed star, brown dwarf, or even a planet.

Why are 90% of all stars on the main sequence?

The answer to why 90% of all stars are on the main sequence can be attributed to a star’s life cycle. On the main sequence, stars are in the stage of their life cycle where their luminosity and temperatures are most stable.

Most stars spend the majority of their lives on the main sequence, as it is usually a very long-lived phase. During this period, atomic fusion of hydrogen at the stellar cores keeps stars in hydrostatic equilibrium and releases large amounts of energy.

For most stars, this is the stage with stabilized temperatures and relatively constant luminosity, permitting them to remain on the main sequence until their fuel supply wanes. Once the star has exhausted most of its hydrogen, it eventually transitions off of the main sequence as it moves into other stages of its life cycle, such as the red giant or white dwarf phases.

During these phases, the stars will have considerably higher luminosity and greater temperatures.

Why do stars spend 90% of their lives as main sequence stars?

Stars spend 90% of their lives as main sequence stars because it is a stable phase where the fusion of hydrogen to helium takes place in the core of the star. During this stage, the star is releasing energy in the form of light and heat and will sustain this energy production as long as the star’s core temperature and pressure remain high enough.

As the star evolves, it will eventually exhaust its supply of hydrogen in the core, causing it to cool and the pressure to drop. This is the beginning of the end of the star’s lifetime. The main sequence is a very stable phase, lasting billions of years, and it is therefore not surprising that it makes up the majority of a star’s time in its lifespan.

Why do low mass stars take much longer to reach the main sequence?

Low mass stars take longer to reach the main sequence because they form over a much longer period of time. Stars form out of the gravitational collapse of gas clouds, and the amount of time it takes for a gas cloud to collapse into a star is dependent on the mass of the gas cloud.

Low-mass stars form from less massive clouds, and therefore they require more time to collapse and form into a star.

Once the star has formed, it still has some way to go before it reaches the main sequence. This is because the star needs to sacrifice its gravitational potential energy and convert it into thermal energy in order to reach the main sequence.

Energy generation in low-mass stars is less efficient than in more massive stars because the initial temperature at the centre is much lower. As a result, the gravitational potential energy is released more slowly for low-mass stars, which takes longer for them to reach the main sequence.

In short, low mass stars take longer to reach the main sequence because they form over a longer period of time, require more time to convert their gravitational potential energy into thermal energy, and because energy generation is less efficient in lower mass stars.

What happens when a star has too much mass?

When a star has too much mass, it reaches a critical point where the outward energy production from fusion can no longer counter the inward pull of gravity. This causes the star to collapse under its own gravity, resulting in a massive explosion known as a supernova.

During a supernova, the star’s core collapses in on itself, heating its material to temperatures of up to 10 billion °C. This leads to dramatic changes in the star’s structure, as it expels much of its mass in the form of high energy particles.

On a larger scale, the supernova’s energy output is immense, and can outshine a whole galaxy of stars. After the supernova fades, the core of the star is left behind, either becoming a neutron star or a black hole.

In some cases, a supernova can even leave behind an exotic object such as a magnetar or quark star. It is these objects, rather than the star itself, that eventually remain after the supernova has concluded.

Why do neutron stars have an upper mass limit quizlet?

Neutron stars have an upper mass limit because of their numerous physical properties. Neutron stars are formed from the collapses of supernovae, and their mass is mostly determined by the mass of their progenitor star.

If a star has a mass greater than approximately three times the mass of our Sun then it will not be able to form a neutron star due to the immense gravitational forces present during a core-collapse supernova.

Beyond this upper limit, the core can no longer withstand the immense gravity exerted upon it, thus creating a black hole. The neutron star’s upper mass limit also has to do with its highest mass-to-radius ratio of any known compact object in the universe.

Neutron stars can have masses larger than three solar masses, but they cannot exceed the Tolman-Oppenheimer-Volkoff limit of approximately three solar masses (TOV limit), or the neutron star’s maximum density becomes unstable and it collapses onto itself.

As the neutron star mass continues to increase, the core’s density will continue to increase as well, eventually becoming too dense for even the neutron degeneracy pressure to oppose gravity’s attempt to collapse it.

This means that neutron stars have an upper mass limit before they are unable to sustain themselves against their own gravity.

Why do only high mass stars go through supernova?

High mass stars go through the supernova process because they are hot and massive enough that their cores are able to undergo nuclear fusion, which releases large amounts of energy in the form of gamma radiation.

This energy can cause the star’s outer layers to collapse in on itself, leading to an explosion known as a supernova. Low mass stars – those below around 8 solar masses – are not massive enough for this process to occur.

Instead, they will eventually cool off and become white dwarfs before eventually fading away into the high vacuum of space.

Why are high mass stars rare?

High mass stars are relatively rare because they burn through their fuel much faster than lower mass stars. As a result, they appear in the Universe far less frequently than stars of lower mass. According to one theory, this is because high mass stars require a near perfect balance of gas and dust in order to form, and there are simply fewer regions of the Universe that meet this criteria.

Additionally, high mass stars are much more energetic, releasing large amounts of energy and radiation which can disrupt the formation of other stars in their vicinity. This means that, even in regions of the Universe with plenty of available material, high mass stars are less likely to form due to the interference of these powerful stellar winds.

Finally, high mass stars have shorter lifetimes, typically lasting for no more than several million years before expending the majority of their hydrogen fuel. This means that, even if conditions in a particular region of the Universe are favorable for the formation of a high mass star, it will not remain in the region for long before beginning to cool and die.

As a result, high mass stars tend to be rarer than their lower mass counterparts.

How do the highest mass stars end their lives quizlet?

The highest mass stars end their lives in very spectacular ways. These stars are large enough that they can become supernovae, which are among the most energetic explosions in the universe. As a star with a mass greater than 8 times that of the Sun runs out of hydrogen fuel it expands, cools and turns into a red giant.

As the core of the star contracts and heats up, the star experiences a catastrophic collapse and an immense amount of energy is released. This energy blows away the outer layers of the star, forming a supernova, leaving behind a neutron star or a blackhole depending on the original mass of the star.

Supernovae can be as bright as an entire galaxy of stars and can be observed from millions of light years away. Because of their short duration, supernovae are very rare, but when they do occur, they are among the most awe-inspiring events in the cosmos.

Why are the very first stars thought to have been much more massive than the Sun?

The very first stars that formed in the Universe are known as Population III stars, which were likely the first generation of stars that were born after the Big Bang. These ancient stars are believed to have been much more massive than the Sun because of their environment at the time of their formation.

The Universe was much denser and metal-free immediately following the Big Bang. This meant that the only elements or atoms that existed were the lightest elements, such as hydrogen and helium, allowing for the formation of these massive stars.

These massive stars were able to achieve such great mass because they had an abundance of other elements to feed on, such as hydrogen and helium, that would provide the stars with the necessary fuel to burn brightly and quickly.

With the lack of heavier elements, these massive stars would’ve gradually begun to build up mass due to nuclear fusion, eventually becoming stars with a core of iron or heavier elements, with masses even greater than eight times that of the Sun.

The sheer size and power of these massive stars would’ve also impacted their shorter lifespans as well, with stars this size only living for a few million years before they eventually exploded and created clouds of gas, from which new stars were born.

This radiation from the explosions of these massive stars is also thought to have been responsible for the formation of galaxies throughout the Universe, with the gas clouds produced from the explosions acting as the building blocks to make new stars and galaxies.

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