MYTUTOR SUBJECT ANSWERS

433 views

How do stars like ours form and die?

Stars are born when gases at high pressure and temperatures begin to burn. They start life out as a big cloud of space junk and debris. Slowly, there's a bit of the cloud with more stuff in it than the other bits so it has a bit more gravitational pull and so slowly, the rest of the cloud gets pulled towards that general area.

But as more of the gas collects there, then there are even more gravitational forces acting so pressure increases and more elements continue to get pulled in. Pressure rises causes the temperature to rise and, once it's hot enough, hydrogen undergoes a nuclear fusion to form helium. This releases energy making it hotter and increases pressure. It also starts a chain reaction so more fusion occurs.

The star can then settle down to a long stable slog with gravity pulling things in balancing with the fusion pressure pushing things out. So there's not much growth and not much really happens. The star is known as a main sequence star. This is the stage our sun is at.

Eventually, however, all good things come to an end and there's no more hydrogen left. So fusion starts to happen with larger elements like helium. Stars like ours expand to become red dwarfs and become hotter. When our sun does this, it will expand to destroy the Earth.

When all the nuclear reactions are done, there's no outward pressure keeping the star big so gravity causes it to collapse into itself forming a white dwarf. Also, no reactions mean no energy so things begin to cool off a bit. And that’s that. Over billions of years, our sun has gone from a cloud to the sun we know and love and will eventually expand to destroy our planet before falling into itself and turning cold. 

Cordelia W. A Level Maths tutor, A Level Further Mathematics  tutor, ...

1 year ago

Answered by Cordelia, a GCSE Physics tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

138 SUBJECT SPECIALISTS

£18 /hr

Luke C.

Degree: Biological Sciences with a year in professional placement (Bachelors) - Exeter University

Subjects offered: Physics, Maths+ 2 more

Physics
Maths
Chemistry
Biology

“My greatest passion is for biology, but I have always enjoyed studying chemistry and mathematics too. Studying these subjects has supported me during my time so far at Exeter University, even though I am still in my first year of stud...”

£18 /hr

Lois M.

Degree: Physics (Masters) - Exeter University

Subjects offered: Physics, Maths

Physics
Maths

“Hi! I'm Lois and I am currently in my second year of studying Physics at the University of Exeter. The past few years of my life have been filled to the brim with maths and physics, so I'm excited to be able to share what I've learned...”

£20 /hr

Timothy G.

Degree: English Literature (Bachelors) - Bristol University

Subjects offered: Physics, English Literature+ 1 more

Physics
English Literature
English Language

“Hi, my name is Tim and I am currently studying English Literature at Bristol University.Since I was young I have been enthusiastic about literature and the English language. I believe literature to be one of the cornerstones of human...”

About the author

Cordelia W.

Currently unavailable: for new students

Degree: Mathematical Science (Masters) - Durham University

Subjects offered: Physics, Maths+ 1 more

Physics
Maths
Further Mathematics

“I LOVE maths and believe I can pass on my love of the subject. I have been teaching maths and physics for years. I taught myself maths and physics, I helped my friends understand both subjects, I went on toteach a whole secondary scho...”

You may also like...

Posts by Cordelia

How do I expand out a pair of brackets?

How do I simplify surds?

How do stars like ours form and die?

How does proof by induction work?

Other GCSE Physics questions

What is the difference between a scalar and a vector?

How to find wave speed from frequency and wave length.

A man decides to shoot a rifle whilst on a wheelchair. Explain in terms of conservation of momentum what happens to the man as the shot is fired.

Explain why the National Grid includes step-up transformers.

View GCSE Physics tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok