LookLook

ThinkThink

DiscussDiscuss

AgreeAgree

ShareShare

WriteWrite

What is today's lesson about? WORDS/NAMES

PROCESSES

CONCEPTS

Write in front of your book

WORDS/NAMES Star, cloud, mass, gravity, atom, energy supernova, pressure, nebula temperature, fusion

PROCESSES : life of a starGravitational Pull, Nuclear fusion,

Learning Learning IntentioIntentio

nnThe Life of a StarThe Life of a Star

Learning objectivesLearning objectives

All(must)

•Describe how and where a star is born (nuclear fusion)•Explain how long a star lives and how it’s death depends on it’s size

Most(Should)

•Show the process of fusion in the birth of a starShow the process of fusion in the birth of a star

•Distinguish between the death of large and small starsDistinguish between the death of large and small stars

•Relate the size of a star to it’s colourRelate the size of a star to it’s colour

Some(could)

Design a diagram to show the complete life cycle of a star

Saturday 22 April 2023

• Write everything you already know, or want to know about the life of a star

• At the end of a lesson we will review what you have learned and how you learnt it

What I know or want to know How I learned it What I have Learned

Birth of a Star

As gravity gets stronger even bigger more material sucked in, making the gravity EVEN strongerAs gravity increases, so the Temperature and Pressure increase. Then…..Nuclear Fusion Occurs

Gravity is the force that pulls things together. More mass in an object= bigger gravity

Gravity pulls atoms together

The atoms in the middle are together so the mass is bigger, which makes gravity bigger

Mass is even bigger so gravity is bigger

1 2

3

Stars begin in clouds of gas and dust.

Gravity pulls the gas and dust atoms together. This makes the gravitational force even bigger stronger

NebulaGravity- how it changesFusionMain sequence star

Nuclear fusion animation

This shows us what nuclear fusion is and how it works

The centre of an hydrogen atom is positively charged meaning they normally repel each other

In a nebulae gravity starts to bring atoms closer this makes the gravity even bigger. As gravity increases, the atoms get hotter. When they are hot enough the atoms collide and FUSE together this forms a new atom (helium)

The newly formed helium atom has less energy than the hydrogen atoms so there is some energy left over this becomes heat and light energy

Fusion starts to occur at 15 million degrees Celsius. At this temperature the outward Force created by the heat balances out the inward force of gravity and the star becomes stable

1 2

3 4

FUSION

How is a star is born?

Write NINE statements/ideas/facts or information about how a star is born (including the role of gravity and fusion then rank them in order of TIME

WHATWHEREWHENHOWWHY

Start

Main Sequence star

Keywords:Star, cloud, mass, gravity, atom, Energy, fusion, pressure, nebula, temperature, Hydrogen,Helium

The real picture...Once you get outside the earths atmosphere this is what you see

• Stars have Different colours

Which indicate different temperatures

Red Orange Yellow Green Blue Violet

Coolest Hottest

• The hotter a star is, the faster it burns its life away.

• Bigger stars are hotter, so Bigger stars are green blue or violet and do not live as long as small ones

• Typically a hot star will live up to 250 million (quarter of a billion years) The sun will live 1000 million (1 billion) and smaller stars even longer

HOW LONG DO STARS LIVE?

The Life of a Star animation (SIMPLE)

LIFE CYCLE OF A STAR ANIMATION 2

The Death of Sun- sized Stars

After the star has used all of the Hydrogen in its core ...the core collapses, making the star expand.It also causes the star to burn LESS quickly and so it turns red

After the remaining gas in the core is used, The outer layers are expelled as a Planetary At centre of Planetary Nebula lies a White Dwarf.It is the size of the Earth with Mass of the Sun “A ton per teaspoon” This eventually burns out leaving a cold mass or black dwarf

The Death of LARGER stars1) Stars That are much bigger than our sun have a much more violent death.Like smaller stars, they fuse hydrogen into helium. However their gravity is bigger so the helium atoms can also fuse (into other elements like carbon and oxygen). These in turn can fuse into even heavier elements like Silicon and carbon

2) As a red supergiant the core of the massive star will look like a giant onion, with the densest material in the middle and the lowest on top. Each shell of the onion will have some small amount of fusion still going on

STARTS HERE

3) With all this fusion going on there is so much energy that the star becomes unstable and EXPLODES (supernova)

4) The result of a supernova is either a neutron star a black hole or a nebula. If a nebula is formed, it is likely a second smaller star could be formed, with other elements from the cloud forming objects that orbit it. This is most likely how our solar system formed

SUMMARY OF The Life Cycles of Stars

KEYPOINTS

IMPORTANT FACTS

EVIDENCE

SUMMARY

The Life cycle of a Star

TEAM ROLES

1) TEAM LEADER

2) TIMEKEEPER

3) CHECKER/SCRIBE

Webpage Task

You Have been asked to provide the scientific information for a webpage containing information for GCSE students about the Life cycle of the sun.

Connor ECCLESTONE Megan FIELDING Elena PRESTI

Megan BRADBURY Samuel BILLINGTONMollie BALDWIN

Kyle BARNETT Dulcie WOOLLISCROFTHarry BLAKEMAN

Ben MarksTegan HYETT Sulaiman AHMAD

Ben GOODYEARJoshua BARNETT Sinead BOWLES

Jack ArdenRachel JONESMarshall BLUE

Charlie ANDERSON Lois ATTWOOD Jacob FOSTER

Archie BOYCEAlex MASON Chloe Brennan Hopkinson

Alice HOULDCROFT

Homework• From what you have learned in todays

lesson summarise the information by producing a diagram to go on the website that gives the overall life cycle of a star

What’s Left After the Supernova

1) Neutron Star/pulsar (If mass of core < 5 x Solar)

2) Black Hole (If mass of core > 10 x Solar)

3) Nebula -Excess cloud of Hydrogen and Dust

Supernova Remnants: SN1987A

a b

c d

a) Optical - Feb 2000• Illuminating material ejected

from the star thousands of years before the SN

b) Radio - Sep 1999c) X-ray - Oct 1999d) X-ray - Jan 2000• The shock wave from the SN

heating the gas

A Red Giant You Know

Which Brings us Back to ...