What is the net result of the CNO cycle quizlet?
What is the net result of the CNO cycle? Four hydrogen nuclei are transformed into one helium nucleus, two neutrinos, and energy.
What is happening inside a star while it expands into a Subgiant quizlet?
What is happening inside a star while it expands into a subgiant? Hydrogen fusion in a shell outside the core generates enough thermal pressure to push the upper layers outward. Why does a star grow larger after it exhausts its core hydrogen? The core quickly heats up and expands.
What is happening deep inside a star while it expands into a Subgiant group of answer choices?
E) Its core contracts, but its outer layers expand and the star becomes bigger but cooler and therefore remains at the same brightness. 12) What is happening inside a star while it expands into a subgiant? A) It is fusing hydrogen into helium in the core. It is fusing hydrogen into helium in a shell outside the core.
What happens to a star after it exhausts its core hydrogen quizlet?
What happens when a star exhausts its core hydrogen supply? A) Its core contracts, but its outer layers expand and the star becomes bigger and brighter.
What happen when a star exhaust its core hydrogen supply?
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 happens when a main sequence star exhausts its core hydrogen fuel supply?
4) What happens when a main-sequence star exhausts its core hydrogen fuel supply? A) The entire star shrinks in size. The core shrinks while the rest of the star expands.
Why does the star swell up as it goes through the life cycle?
When the hydrogen in the centre of the star is depleted, the star’s core shrinks and heats up. This causes the outer part of the star, the star’s atmosphere, which is still mostly hydrogen, to start to expand. The star becomes larger and brighter and its surface temperature cools so it glows red.
Can a white dwarf ever produce a supernova?
The most massive stars, with eight times the mass of the sun or more, will never become white dwarfs. Instead, at the end of their lives, they will explode in a violent supernova, leaving behind a neutron star or black hole. They simply burn through all of their hydrogen, ending the process as a dim white dwarf.
What happens to a massive star during the pre main sequence?
Once the outward force caused by thermal pressure is balanced by the inward force of gravity (a condition known as hydrostatic equilibrium), a pre-main sequence star ceases to collapse and a star is born. Main sequence stars are those stars fusing hydrogen into helium in their cores.
What are the six stages of a star?
Formation of Stars Like the Sun
- STAGE 1: AN INTERSTELLAR CLOUD.
- STAGE 2: A COLLAPSING CLOUD FRAGMENT.
- STAGE 3: FRAGMENTATION CEASES.
- STAGE 4: A PROTOSTAR.
- STAGE 5: PROTOSTELLAR EVOLUTION.
- STAGE 6: A NEWBORN STAR.
- STAGE 7: THE MAIN SEQUENCE AT LAST.
Which main sequence stars are the least massive?
stars on the main sequence are powered by hydrogen fusion, which takes place in their cores, and the main sequence is just a sequence of mass (faint red stars are the least massive – starting at around one-tenth that of the Sun – and bright blue ones the most – about 20 times).
What type of stars are the least massive?
The smallest stars around are the tiny red dwarfs. These are stars with 50% the mass of the Sun and smaller. In fact, the least massive red dwarf has 7.5% the mass of the Sun. Even at this smallest size, a star has the temperature and pressures in its core so that nuclear fusion reactions can take place.
What is the final stage in the evolution of the most massive stars?
The final fate of a very massive star, whether it explodes as core collapse supernova, as pair instability supernova, as black-hole accretiondriven supernova, as gamma-ray burst, or just collapses to a black hole, depends on how much mass the star has left when it reached the end of its evolution.
Why are 90% of stars on the main sequence?
Main sequence stars fuse hydrogen atoms to form helium atoms in their cores. About 90 percent of the stars in the universe, including the sun, are main sequence stars. Stars start their lives as clouds of dust and gas. Gravity draws these clouds together.
Which is the biggest star in the universe?
Answer: The largest known star (in terms of mass and brightness) is called the Pistol Star. It is believed to be 100 times as massive as our Sun, and 10,000,000 times as bright! In 1990, a star named the Pistol Star was known to lie at the center of the Pistol Nebula in the Milky Way Galaxy.
Which main sequence stars are the most massive color?
Temperature translates to color, and this relationship between color and brightness (luminosity) for hydrogen-burning stars is called the main sequence. Massive hydrogen-burning stars are blue-white, the Sun is yellow, and low-mass stars are orange and red.
What is the dominant factor in the life of a star?
To understand the stars, you must understand pressure. From birth to death, the internal pressure of a star created by its own weight is the most dominant factor in the star’s life.
What is the meaning of Zero Age Main Sequence?
Zero Age Main Sequence (ZAMS) is the time when a star first joins the main sequence on the Hertzsprung-Russell diagram (HR diagram) by burning hydrogen in its core through fusion reactions.
What is the difference between a giant star and a supergiant star?
What is the difference between a giant star and a supergiant star? Giant stars have radii between 10 and 100 solar radii and luminosities between 10 and 1,000 times that of the Sun. Whereas Supergiants have radii between 30 and 1,000 solar radii and luminosities between 30,000 and 100,000 times that of the Sun.
What is a giant star called?
Subclasses of giants are supergiants, with even larger radii and brightness for their masses and temperatures (see supergiant star); red giants, which have low temperatures but are of great brightness; and subgiants, which have slightly reduced radii and brightness.
What star is the hottest supergiant?
Blue supergiants are supergiant stars (class I) of spectral type O. They are extremely hot and bright, with surface temperatures of between 20,000 – 50,000 degrees Celsius. The best known example is Rigel, the brightest star in the constellation of Orion.
What is the definition of red giant?
A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ( M ☉)) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around 5,000 K (4,700 °C; 8,500 °F) or lower.