- Nuclear fusion.
- Out of fuel.
- Fusion stops, temperature drops.
- Core contracts (gravity pulling atoms in).
- Increased temperature (more atoms, more collisions) and density in the core reinitiates nuclear fusion, equilibrium is achieved, and the cycle begins again at step 1.
What is it called when a star is in equilibrium?
This pressure counteracts the force of gravity, putting the star into what is called
hydrostatic equilibrium
.
What is the beginning of the end for main sequence stars?
The beginning of the end for a main sequence star is
when the core runs out of fuel for the fusion process
.
What is necessary for a star to remain stable?
All stars are the result of a balance of forces: the force of gravity compresses atoms in interstellar gas until the fusion reactions begin. … As long as
the inward force of gravity and the outward force generated by the fusion reactions are equal
, the star remains stable.
What is gravitational equilibrium How does the sun and other stars achieve it?
According to our current model of solar-energy gener- ation by nuclear fusion,
the Sun maintains its size through a balance between two competing forces: gravity pulling inward and pressure pushing outward
. This balance is called gravitational equilibrium (or hydrostatic equilibrium).
What are the 7 main types of stars?
There are seven main types of stars. In order of decreasing temperature,
O, B, A, F, G, K, and M
. This is known as the Morgan–Keenan (MK) system.
What is star life cycle?
A star’s life cycle is
determined by its mass
. The larger its mass, the shorter its life cycle. A star’s mass is determined by the amount of matter that is available in its nebula, the giant cloud of gas and dust from which it was born.
What happens when a star is not in equilibrium?
Once a star has exhausted its supply of hydrogen in its core, leaving nothing but helium,
the outward force created by fusion starts to decrease
and the star can no longer maintain equilibrium. The force of gravity becomes greater than the force from internal pressure and the star begins to collapse.
What is the star life cycle that is accurate?
The correct life cycle is:
Star of one stellar mass, red giant, white dwarf, planetary nebula
.
What keeps a star a size stable unchanging?
Lesson Summary
You can imagine a star as a series of layers.
The inward force of gravity is balanced out by the outward force of pressure
to keep the star stable. This stable balance, the outward pressure of hot gases balancing the inward pull of gravity is called the hydrostatic equilibrium.
How are stars made step by step?
- Star Formation Shapes the Appearance of the Universe and Provides the Sites for Planets.
- Step 1: initial collapse of an interstellar cloud.
- Step 2: the cloud fragments into clumps . The fragmentation is related to turbulence in the collapsing cloud. ( …
- Step 3: The clumps collapse into a stars.
How long does a star live for?
Generally, the more massive the star, the faster it burns up its fuel supply, and the shorter its life. The most massive stars can burn out and explode in a supernova after only a few million years of fusion. A star with a mass like the Sun, on the other hand, can continue fusing hydrogen for
about 10 billion years
.
What happens when a star forms?
Stars form from an accumulation of gas and dust, which
collapses due to gravity
and starts to form stars. … Stars are born and die over millions or even billions of years. Stars form when regions of dust and gas in the galaxy collapse due to gravity. Without this dust and gas, stars would not form.
What is the 11 year solar cycle?
The Sun’s magnetic field goes through a cycle, called the solar cycle. Every 11 years or so,
the Sun’s magnetic field completely flips
. This means that the Sun’s north and south poles switch places. Then it takes about another 11 years for the Sun’s north and south poles to flip back again.
Why is the Sun in equilibrium?
The Sun, like the majority of other stars, is
stable
; it is neither expanding nor contracting. Such a star is said to be in a condition of equilibrium. All the forces within it are balanced, so that at each point within the star, the temperature, pressure, density, and so on are maintained at constant values.
Why does the Sun shine?
The Sun shines
by turning hydrogen into helium in its core
. This process is called nuclear fusion. Fusion happens when lighter elements are forced together to become heavier elements. When this happens, a tremendous amount of energy is created.
