LookThinkDiscussAgreeShareWrite 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 star Gravitational Pull, Nuclear fusion,

Learning Intention The Life of a Star Learning 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 Sunday, 06 December 2015

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 itWhat I have Learned

Birth of a Star As gravity gets stronger even bigger more material sucked in, making the gravity EVEN stronger As 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 Stars begin in clouds of gas and dust. Gravity pulls the gas and dust atoms together. This makes the gravitational force even bigger stronger Nebula Gravity- how it changes Fusion Main 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 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 WHAT WHERE WHEN HOW WHY 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 stars 1) 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 1)How a star is born 2)How Long a Star lives 3)How small stars die 4)How large stars die 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 BILLINGTON Mollie BALDWIN Kyle BARNETT Dulcie WOOLLISCROFT Harry BLAKEMAN Ben Marks Tegan HYETT Sulaiman AHMAD Ben GOODYEAR Joshua BARNETT Sinead BOWLES Jack Arden Rachel JONES Marshall BLUE Charlie ANDERSON Lois ATTWOOD Jacob FOSTER Archie BOYCE Alex 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 ab cd a) Optical - Feb 2000 Illuminating material ejected from the star thousands of years before the SN b) Radio - Sep 1999 c) X-ray - Oct 1999 d) X-ray - Jan 2000 The shock wave from the SN heating the gas

A Red Giant You Know

Which Brings us Back to...