In a massive star, hydrogen fusion in the core is followed by several other fusion reactions involving heavier elements. Just before it exhausts all sources of energy, a massive star has an iron core surrounded by shells of silicon, sulfur, oxygen, neon, carbon, helium, and hydrogen.
What are the 5 stages of a high mass star?
The exact stages of evolutions are:
- Subgiant Branch (SGB) – hydrogen shell burning – outer layers swell.
- Red Giant Branch – helium ash core compresses – increased hydrogen shell burning.
- First Dredge Up – expanding atmosphere cools star – stirs carbon, nitrogen and oxygen upward – star heats up.
What are the 7 stages of a high mass star?
Seven Main Stages of a Star
- Giant Gas Cloud. A star originates from a large cloud of gas.
- Protostar. When the gas particles in the molecular cloud run into each other, heat energy is produced.
- T-Tauri Phase.
- Main Sequence.
- Red Giant.
- The Fusion of Heavier Elements.
- Supernovae and Planetary Nebulae.
What is the main sequence of a high mass star?
High mass stars (stars with masses greater than three times the mass of the Sun) are the largest, hottest and brightest Main Sequence stars and blue, blue-white or white in colour. High mass stars use up their hydrogen fuel very rapidly and consequently have short lives.
What happens in a high mass star?
High mass stars go through a similar process to low mass stars in the beginning, except that it all happens much faster. Then unlike low mass stars, they have enough mass that gravity contracts the core raising the temperature and carbon can fuse into neon, then neon into oxygen, then oxygen into silicon, then iron.
What are two characteristics of high mass stars?
High-mass star characteristics include:
- Very high-core temperatures.
- Crushing stellar-core pressures.
- Very big and very bright,
- Ends its stellar life with a bang.
What is the first stage of a high mass star?
Small stars have a mass upto one and a half times that of the Sun. Stage 1- Stars are born in a region of high density Nebula, and condenses into a huge globule of gas and dust and contracts under its own gravity.
What is T Tauri stage?
Slowly, stellar winds and radiation blow away the surrounding shell of gas and dust, and the third stage, when the surrounding envelope has cleared, is called the T-Tauri phase. …
What elements do high mass stars produce?
The oxygen and heavier elements in our bodies were made in the nuclear furnace of high mass stars. High core temperatures allow helium to fuse with heavier elements. allow fusion to elements as heavy as iron. Advanced reactions in stars make elements like Si, S, Ca, and Fe.
What are 2 characteristics of high mass stars?
What can happen to a high mass star when it dies?
When a high-mass star has no hydrogen left to burn, it expands and becomes a red supergiant. While most stars quietly fade away, the supergiants destroy themselves in a huge explosion, called a supernova. The death of massive stars can trigger the birth of other stars.
How do scientists identify high mass stars?
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. As the main sequence star glows, hydrogen in its core is converted into helium by nuclear fusion.
What are the characteristics of high-mass stars?
High-mass stars • Reach the main-sequence in less than 150000 years. • Strong gravity compresses the hydrogen core to much higher temperatures than in low-mass stars. • Fusion rate increases with temperature. • In a high-mass star, hydrogen fusion occurs through the CNO cycle rather than through the proton-proton chain
What can the H-R diagram tell us about the stars?
The White Dwarfs and Red Giants are different classes of stars that the H-R diagram helps us to identify. So the H-R diagram can tell us something about the size (radius) of the stars.
How do stars form from low mass?
– All stars form as low-mass stars. – Stars continue accreting gas until it is all deple ted. – Some stars accrete more efficiently and grow to fo rm high-mass stars. • As with low-mass stars, hydrogen burning begins when the gravitational contraction makes the core hot enough for hydrogen fusion.
How long do high-mass stars live?
• The incredibly rapid fusion rates mean that high-mass stars cannot live very long. – A 25 solar mass star only spends a few million yea rs on the main-sequence (Remember the sun spends 10 billion years on the main sequence). • When the core hydrogen is exhausted a high-mass star behaves like a low- mass star, only faster.
