the condition where the weight of a star and the gas pressure are balanced is called

The Condition Where The Weight Of A Star And The Gas Pressure Are Balanced Is Called?

Terms in this set (21)

The condition where the weight of a star and the gas pressure are balanced is called __________ hydrostatic equilibrium. Which of the following statements best describes the gas pressures inside of stars? The gas pressure is greatest at the center and decreases toward the star surface.

What percentage of a star’s total fusion lifetime is spent as a main sequence star?

The overall lifespan of a star is determined by its mass. Since stars spend roughly 90% of their lives burning hydrogen into helium on the main sequence (MS), their ‘main sequence lifetime’ is also determined by their mass.

Which property of a star directly indicates the rate at which energy is produced inside that star?

Luminosity. Perhaps the most important characteristic of a star is its luminosity—the total amount of energy at all wavelengths that it emits per second. Earlier, we saw that the Sun puts out a tremendous amount of energy every second. (And there are stars far more luminous than the Sun out there.)

Which stars produce most of their energy by the CNO cycle quizlet?

. The rate of the CNO cycle is more temperature sensitive than the proton-proton chain.) Which stars produce most of their energy by the CNO cycle? Upper main sequence stars.

Which of the following stars will spend the most time as a main sequence star quizlet?

The sudden onset of helium fusion in the cores of some giant stars. Blue main sequence stars have ___________ than red main sequence stars.

Why does a star’s life expectancy depend on mass?

Why does a star’s life expectancy depend on mass? More massive stars have shorter lifetimes because their larger masses cause them to consume their fuel faster. … The more massive a star is, the higher the rate of fusion in the core is due to the larger weight pressing down on the inner layers.

What places a limit on the lifetime of a star?

What places a limit on the lifetime of a star? core hydrogen fusion. You just studied 20 terms!

Why are about 90% of the stars we observe on the main sequence?

Being on the main sequence means that the star is converting hydrogen to helium in the core. Since stars are made mostly of hydrogen, this process takes approximately 90% of a star’s life. Thus it makes sense that the 90% of the stars observed at some particular time would be undergoing this process.

How do astronomers determine the luminosity of a star?

However, the brightness of a star depends on its composition and how far it is from the planet. Astronomers define star brightness in terms of apparent magnitude — how bright the star appears from Earth — and absolute magnitude — how bright the star appears at a standard distance of 32.6 light-years, or 10 parsecs.

How do you think the luminosity of a star is related to its temperature?

Predict: How do you think the luminosity of a star is related to its temperature? As the size of a star increases, luminosity increases. … That increased surface area allows more light and energy to be given off. Temperature also affects a star’s luminosity.

How does the CNO cycle differ from the proton proton chain?

The CNO cycle produces a helium nucleus, whereas the proton-proton chain does not. The CNO cycle produces energy, whereas the proton-proton chain does not. The CNO cycle uses a carbon nucleus as a catalyst for the reaction, whereas the proton-proton chain does not. The CNO cycle requires higher temperatures.

Under what conditions might interstellar gas clouds collapse to form stars quizlet?

stars form when an interstellar cloud collapses under its own gravity and breaks up into pieces comparable in mass to our sun. heat, rotation, and magnetism all compete with gravity to influence the cloud’s evolution.

Why do nuclear fusion reactions only take place in the interior of a star?

Higher mass stars burn through their nuclear fuel faster. Why do nuclear fusion reactions only take place in the interior of a star? The temperature is the hottest in the center.

Which of the following stars will spend the longest time on the main sequence?

Science Chapter 26

A	B
Which kind of star is most likely to spend the longest time on the main sequence?	a low-mass red star
Low-mass and medium-mass stars eventually turn into _______.	white dwarfs
What is a spinning neutron star emitting radio waves?	pulsar
The sun’s major source of fuel is _____.	hydrogen

Which of the following stars is the hottest based on spectral classification alone?

M stars are the coldest and O stars are the hottest in stellar classification. These stars are from the main sequence.

Why does a star grow larger in radius immediately after it exhausts its core hydrogen?

Why does a star grow larger after it exhausts its core hydrogen? The core quickly heats up and expands.

How does a star’s mass determine its lifespan?

A star’s mass determines its lifespan because the rate at which hydrogen fusion occurs depends on how much pressure the star has on its core. … Both hydrogen and helium rise up through the star and then fall back down. Itcan last a trillion years.

Why do think massive star has shorter life span than average star?

Massive stars live shorter lives than the common small stars because even though they have a larger amount of hydrogen for nuclear reactions, their rate of consuming their fuel is very much greater.

Why do all stars spend most of their lives on the main-sequence?

Why do all stars spend most of their lives on the main sequence? Because the fuel for energy production in this stage of the star’s life is hydrogen and that is an element every star has lots and lots of. … elements beyond carbon and oxygen? Because they just cannot get hot enough for the fusion of heavier nuclei.

Will our Sun become a black hole?

Will the Sun become a black hole? No, it’s too small for that! The Sun would need to be about 20 times more massive to end its life as a black hole. … In some 6 billion years it will end up as a white dwarf — a small, dense remnant of a star that glows from leftover heat.

What are the 3 different ways a star can end its life?

Cards

Term Stars can end their lives in three ways, List	Definition White Dwarf Neutron Star Black Hole
Term How a star ends its life depends on	Definition It’s Mass!

Why do stars have colors?

The color of a star is linked to its surface temperature. The hotter the star, the shorter the wavelength of light it will emit. The hottest ones are blue or blue-white, which are shorter wavelengths of light. Cooler ones are red or red-brown, which are longer wavelengths.

How does the mass vary along the main sequence?

How does mass vary along the main sequence? A star’s mass determines the star’s temperature. The higher the mass of the star, the shorter the life. … It varies with mass because the higher the mass of the star the short the main sequence lifetime.

Why does a star leave the main sequence?

Leaving the Main Sequence

When stars run out of hydrogen, they begin to fuse helium in their cores. This is when they leave the main sequence. High-mass stars become red supergiants, and then evolve to become blue supergiants. It’s fusing helium into carbon and oxygen.

Why are most stars found in the main sequence of the HR diagram?

The main sequence stretching from the upper left (hot, luminous stars) to the bottom right (cool, faint stars) dominates the HR diagram. … Stars enter this evolutionary stage once they have exhausted the hydrogen fuel in their cores and have started to burn helium and other heavier elements.

What two things do astronomers need to know about a star to calculate its luminosity and absolute magnitude?

Using equation 4.6 all we need in order to calculate the intrinsic luminosity of a star is its effective temperature and its radius.

What two factors determine luminosity?

Two factors determine the brightness of a star:

luminosity – how much energy it puts out in a given time.
distance – how far it is from us.

WHAT IS A stars luminosity quizlet?

luminosity- The luminosity of a star is the amount of light it emits from its surface. apparent brightness-how bright the star appears to a detector here on Earth.

What is the relationship between luminosity and location on the HR diagram?

The spectral class gives the star’s relative temperature, hence its horizontal location in the H-R Diagram. The luminosity class gives the star’s relative luminosity at a given temperature, hence its vertical location in the H-R diagram.

How is a star’s luminosity related to its energy?

The luminosity of a star is a measure of its brightness. … Astronomers measure a star’s brightness by examining the amount of energy emitted (given off) every second. The more energy emitted, the higher the brightness. Scientists use Watts to measure energy.

What does luminosity mean?

Definition of luminosity

1a : the quality or state of being luminous. b : something luminous. 2a : the relative quantity of light. b : relative brightness of something. 3 : the relative quantity of radiation emitted by a celestial source (such as a star)

Which process describes correctly the CNO cycle?

The ‘CNO cycle’ refers to the Carbon-Nitrogen-Oxygen cycle, a process of stellar nucleosynthesis in which stars on the Main Sequence fuse hydrogen into helium via a six-stage sequence of reactions. This sequence proceeds as follows: A carbon-12 nucleus captures a proton and emits a gamma ray, producing nitrogen-13.

What does the CNO cycle and the hydrogen proton-proton cycle have in common?

What does the CNO cycle and the hydrogen proton-proton cycle have in common? … They both are ways to fuse hydrogen nuclei to make helium. What change slowly occurs during the main-sequence lifetime of a star? Its core temperature slowly increases, increasing the fusion rate and hence the luminosity.

Why does the CNO cycle require a higher temperature than the proton-proton chain?

Because a carbon nucleus has a charge of 6, it strongly repels an approaching proton. Therefore, the CNO cycle requires a much higher temperature than the proton-proton chain, to overcome the stronger Coulomb barrier.

the condition where the weight of a star and the gas pressure are balanced is called