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Stars and Galaxies. Topic: Our Sun Objectives: Day 1 of 4 I will learn the definition of a star I will learn the process of fusion in the sun’s core I.

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Presentation on theme: "Stars and Galaxies. Topic: Our Sun Objectives: Day 1 of 4 I will learn the definition of a star I will learn the process of fusion in the sun’s core I."— Presentation transcript:

1 Stars and Galaxies

2 Topic: Our Sun Objectives: Day 1 of 4 I will learn the definition of a star I will learn the process of fusion in the sun’s core I will be able to distinguish between the inner and outer layers of the sun Unit: Stars & Galaxies

3 Quickwrite: Answer one of the questions below in 1-2 sentences: What do you think fuels the sun???? A big tank of gas??? Nuclear energy???? How long do you think it takes light to reach earth from the sun???? How do you think energy from the sun reaches earth???

4 Radio Waves & Microwaves Infrared (heat) Visible LightUltra VioletX-RaysGamma Rays Radio Waves Radio Waves are given off by the Sun. These are long wavelength waves and create the static you get on your radios and TV’s Infrared Infrared or heat waves have a shorter wavelength than radio waves. Heat Waves or radiation form the sun is what controls our weather Light Visible Light from the Sun has an even shorter wavelength. Light waves are the only type of radiation we can see. Ultra Violet (UV) radiation from the Sun has an even shorter wavelength. UV Radiation is absorbed by the earth’s ozone layer & can cause skin cancer X-Rays Due to their short wavelength, X-Rays are even more hazardous to your health. This is why doctor’s put a lead vest over you when you get X-rays for an injury Gamma Gamma Radiation has the shortest wavelengths of all radiation and is therefore Just small amounts can be fatal.

5 What is a Star? A sphere of gases that produces heat and light through the ____ of hydrogen Our sun is average star Answer Bank stars Transfer Cool fusion photosphere 4

6 Inner layers Core Radiative Zone Convection Zone

7 Core The core lies in the heart of the sun and is 15,600,000 degrees Celsius The nuclear process know as hydrogen fusion occurs in the core During Hydrogen Fusion, 4 hydrogen combine to form 1 helium nucleus releasing tremendous amounts of energy energy4 H = 1 He + energy Think Hydrogen Bomb!Think Hydrogen Bomb!

8 H H H H He In the Core, Pressures and Temperatures are high enough for Fusion to take place Fusion occurs when 4 hydrogen atoms (light element) combines to form 1 Helium atom (heavier element) Hydrogen, a lighter element is converted into a heavier element, helium In the process, energy is released in the form of light &radiation The core, where nuclear fusion takes place let’s zoom in and what happens

9 What is Fusion? Answer Bank stars Transfer Cool photosphere 4 H H H H He H H H H H H H H H H H H The combining of lighter elements to form heavier elements In the Sun’s core, ___ hydrogen atoms (a light element [don’t write] ) combine to form 1 helium atom (a heavier element [don’t write] ) & energy is released

10 Radiative Zone In the radiative zone, energy moves radiates outward from the core in the form of light & radiation It takes light thousands of years to move from the core to the next layer Temperature is 8,000,000 degrees Celsius

11 Convection Zone Energy moves through this zone by convection Hot gases rise toward the surface while cooler gases sink back down It’s behaves like a giant pot of boiling water Temp = 2,000,000 degrees Celsius

12 Outer Layers Photosphere Chromosphere Corona (not visible)

13 Photosphere Often called the surface of the sun Where light is given off Temperatures are around 6,000 degrees Celsius

14 Chromosphere Above the photosphere is the chromopshere It’ temperature is 20,000 degrees Celsius Reddish in color

15 Corona Largest layer of the sun Extends millions of kilometers in to space Hottest layer Temp= 2,000,000 C ° Charged particles leave the corona creating a solar wind

16 The Corona seen during an eclipse

17 What are the Layer’s of the Sun? Core- produces energy from _______ Fusion Radiative Zone Convection Zone Photosphere- gives off light, surface of the sun Chromosphere Corona- seen during an_____, gives off solar wind Answer Bank stars Transfer Cool hydrogen 4 eclipse

18 Sunspots “Cool” dark areas on the Sun’s surface By studying sunspots, we have discovered that the Sun rotates Sunspots can last from a few days to a few months They represent areas of intense Magnetic activity

19 Sunspots “Cool” dark areas on the Sun’s surface By studying sunspots, we have discovered that the Sun rotates Sunspots can last from a few days to a few months They represent areas of intense Magnetic activity

20 Every 11 years our sun goes through a Sunspot cycle Our Sun has periods of sunspot maximums where many sunspots are visible Our Sun also has periods of sunspot minimums where only a few sunspots are visible Sunspot Cycle Maximums and Minimums

21 Solar Flares A solar flare is a violent explosion in the Sun's atmosphere Sun They release tremendous amount of radiation or energy in the form of UV Rays, X-rays, and gamma rays

22 Prominences Prominences are huge arching columns of gas on the surface of the sun They erupt at speeds ranging from km/s Ultraviolet light and x-rays from prominences can reach earth and cause disruption in radio signals

23 What Features can be found on the Sun? Sunspots –_____dark areas on the surface of the sun that occur in an 11 year cycle (maximums/minimu ms) Prominences – Huge arching columns of gas Solar Flares –violent ____ of energy (radiation) Answer Bank stars Transfer bursts Cool photosphere 4

24 Summarize: Our sun is a star made mostly of ______ and helium gases _____ is the combining of lighter elements to form _____ elements In the Sun’s____, 4 hydrogen atoms a combine to form 1 ____ atom & energy is released Answer Bank heavier Hydrogen fusion Helium core

25 Topic: Light years & Stars Objectives: Day 2 of 4 I will understand the concept of a light year and how we use them to measure distances to Stars and galaxies I will understand how stars vary in their size, color, temperature and brightness I will learn how to classify stars on a H-R Diagram Unit: Stars & Galaxies

26 Quickwrite: Answer one of the questions below in 1-2 sentences: If you were traveling at the speed of light, how many times do you think you could go around the earth in one second???? If a star 10 light years away exploded today, how long would it take you to see it???? Compared to other stars, do you think our sun is hot or cool star??? Large or small star????

27 Light Years When astronomers first realized how far away stars actually are, it became apparent that a new unit of measurement would be needed to record their distances Stars are much farther away than the planets in our solar system Distances between stars are measured in light years!

28 Light Years A light year is the distance that light travels in a year We use the light year to measure very distant objects such as stars and galaxies Light travels at 300,000 km/s or about 9,500,000,000,000 trillion kilometers in one year (9.5 x km/yr) 299,792 km/ s Nothing is faster than light If you travel at the speed of light, you would become light

29 How Fast is That? A traveler, moving at the speed of light, would circum-navigate the equator approximately 7.5 times in one second How long do you think it takes light to reach Earth from the Sun?

30 What are Light Years? A light yr is the distance that light travels in a ______ In 1 yr, light travels 9.5 trillion kilometers or 300,000 km/s Light years are used to measure very distant objects such as stars and galaxies Answer Bank Average Temperature Absolute Distance Year 90% hot

31 Parallax! How do we know the stars are farther away than the planets in our solar system? We use parallax! parallaxThe distance of a star is found by using parallax ParallaxParallax is the apparent shift in the position of an object when viewed from two different positions You can easily observe parallax Hold your hand at arm’s length and look at one finger with your left eye and then with your right eye What you will notice is that your finger appears to change position with respect to the background

32 Parallax Continued….. Now try the same experiment with your finger closer to your face What do you observe? The closer an object is to the observer, the greater its parallax We can measure parallax of relatively close stars in order to determine their distance from earth

33 Calculating Parallax

34

35 What is Parallax? Parallax is how we measure the ____ to stars in light years It is found by viewing an object from 2 fixed locations Answer Bank Average Temperature Absolute Distance Year 90% hot

36 Blue Stars are large hot and bright Star Characteristics Red Stars are small cool and dim Yellow Stars like are Sun are average in brightness & temperature

37 Large Blue-white stars are ___ & bright Red stars are cool & dim Yellow stars, like our sun are ____ in temperature and bright ness What’s the relationship between star color, size, & temperature? Answer Bank Average Temperature Absolute Distance Year 90% hot

38 H-R Diagram In the early 1900’s, Ejnar Hertzsprung and Henry Russell found a way to classify stars They classified stars by their temperature and brightness =HEheh1BH34Q&feature=fvw =HEheh1BH34Q&feature=fvw Hot White Dwarfs Red Dwarfs Sun Blue Massive Stars Giants Supergiants Cool Red Dim Stars Hot Bright Blue Stars Yellow Orange Average Stars

39 H-R Diagram Hertzsprung and Russell came up with a graph that shows the relationship between temperature and brightness Notice where the cool small red dwarfs stars are located Notice where the massive hot blue dwarfs stars are located Hot White Dwarfs Red Dwarfs Sun Blue Massive Stars Giants Supergiants Cool Red Dim Stars Hot Bright Blue Stars Yellow Orange Average Stars

40 What is the H-R Diagram? A graph that compares the brightness, ______ and color of a star _____ magnitude is the true brightness of a star Answer Bank Average Temperature Absolute Distance Year 90% hot

41 Main Sequence Stars Our sun is a yellow Main Sequence Star Main Sequence Stars that fit into a diagonal band that run from the upper left to the lower right corner Main Sequence Stars contain large, hot blue stars, as well as small cool red stars 90 % of all stars are Main Sequence Red Dwarfs Sun Blue Massive Stars Cool Red Dim Stars Hot Bright Blue Stars Yellow Orange Average Stars

42 What are Main Sequence Stars? The diagonal band of stars in an H-R diagram Blue, white, yellow, orange, red stars ____ of the stars we see at night are main sequence Answer Bank Average Temperature Absolute Distance Year 90% hot

43 Summarize: _______ is how we measure star distances when viewed from two fixed locations as we orbit the sun Large stars are ____ and small stars are ____ Hot stars are ______ in color Cooler stars are ______in color An H-R diagram is a graph that relates star ________ to star ________ Answer Bank Brightness temperature Parallax bright Absolute blue red dim

44 Topic: Star Lifecycle Objectives: Day 3 of 4 To learn the difference between the lifecycle of a massive blue main sequence star with a yellow main sequence star like our sun To understand how nucleosynthesis occurs in stars Star size: H34Q Unit: Stars & Galaxies

45 Quickwrite: Answer one of the questions below in 1-2 sentences: What do you think will happen to our Sun when it runs out of hydrogen fuel????? Everything around us is made of elements. Where do you think these elements are made???? Why do you think some star’s become black hole’s and other like Sun do not????

46 All star’s form in a nebula A star will begin it’s main sequence when hydrogen fusion begins But what determines the size of a star? Gravity wants to crush the star So why doesn’t it? Because the outward pressure Or force of energy from Fusion balances out the inward force of gravity This keeps the star in a state of balance or equilibrium! Star Size

47 What determines the size of a main sequence star? A balance between the ____ pull of gravity and the outward push of energy created by fusion Answer Bank Neutron Lighter Inward Red Fusion White dwarf short

48 Star like our sun have average lives average lives Small Red dwarf stars have long lives because of cooler temperatures temperatures in the core Large massive blue stars have Short lives Because they have higher pressures & temperatures in the Core, therefore they run through their Hydrogen fuel source faster Hydrogen Empty Full Hydrogen Empty Full Hydrogen Empty Full Temperature & Pressure Affect Star Life

49 How does temperature and pressure effect the life of a star? Temperature and pressure increase the rate of fusion in a stars core Hot blue stars have ____ lives Cooler ___ stars have long lives Yellow stars like our sun have average lives Answer Bank Neutron Lighter Inward Red Fusion White dwarf short

50 Helium In a massive blue stars core, hydrogen fuses together to form Helium for most of its short Main sequence life Eventually hydrogen starts to run out and helium starts to accumulate Carbon Helium Over time the outward pressure or force of energy from fusion becomes stronger than the inward force of gravity & the star begins to swell & cool changing its color in the process Massive Blue Star Lifecycle As a result gravity wants to crush the star, pressures & temperatures increase, & the star begins fusing helium into carbon

51 Temperatures continue to increase in the core, & the star begins fusing Carbon into Oxygen Carbon Helium Oxygen Carbon Helium Hydrogen At this point the star is now a supergiant But fusion doesn’t stop Just yet!!!!! Massive Blue Star Lifecycle

52 Carbon Helium Oxygen Carbon Helium Hydrogen Iron Oxygen Carbon Helium Hydrogen Finally, as temperatures continue to increase the star will begin fusing oxygen into Iron Near the end of it’s life The blue massive star resembles an onion with layers of different elements This process is called Nucleosynthesis—Where Lighter are elements are created into heavier elements through Fusion in a star Massive Blue Star Lifecycle

53 Carbon Helium Oxygen Carbon Helium Hydrogen Iron Oxygen Carbon Helium In massive blue stars Elements up to the size of Iron-element 26 are created Through fusion Massive Blue Star Lifecycle

54 Carbon Helium Iron Oxygen Carbon Helium Hydrogen At a certain temperature, Fusion can no longer occur and the outward energy stops, at this point gravity takes Over and crushes the star The star explodes into a super nova !!! Depending upon the stars initial mass or size, It will end up as either a neutron star or Black hole Black HoleNeutron Star Massive Blue Star Lifecycle

55 Carbon Helium Iron Oxygen Carbon Helium Hydrogen When the star explodes, it blasts all The elements into space, seeding the universe with Elements to make new stars, planets, people and buildings Supernovas are so hot & bright, They produce all other elements heavier than iron Massive Blue Star Lifecycle

56 What is Nucleosynthesis? The creation of new elements in stars by fusing lighter elements into heavier elements (fusion) –Fusion in Blue Massive stars create elements as heavy as ______ –At this point fusion stops and the star goes supernova –When a super giant star goes supernova (explodes) it creates elements _____than Iron such as gold and lead Answer Bank Neutron Lighter Inward Red Iron heavier short

57 Yellow Star (Sun) Star Lifecycle Helium Carbon Helium Carbon Helium Over time the outward pressure or force of energy from fusion becomes stronger than the inward force of gravity & the star begins to swell & cool changing its color in the process Throughout this time Helium Will accumulate in its core Our sun’s core will fuse hydrogen into Helium for most of its 10 billion year old Main sequence life As a result of gravity crushing the star, pressures & temperatures increase & the star begins fusing helium into carbon

58 Helium Carbon Helium Oxygen Carbon Helium Hydrogen Temperatures continue to increase in the core, & the star begins fusing Carbon into Oxygen At this point the star is now a Red Giant Unlike a blue star, temperatures and pressure are not high enough To produce Iron through fusion Fusion stops at OXYGEN Yellow Star (Sun) Star Lifecycle

59 Helium Carbon Helium Oxygen Carbon Helium Hydrogen Instabilities in the balance Between Gravity & outward force or Pressure of fusion result in abrupt explosions that blow away the outer layers of the star The result is a planetary nebula with a hot white dwarf star in the middle Yellow Star (Sun) Star Lifecycle

60 Eventually the Gases are expelled Leaving behind A white dwarf star A white dwarf star is what remains of an average star like our sun after Running out of fuel It’s about the size of earth Yellow Star (Sun) Star Lifecycle

61 Summarize: ???? Answer Bank White dwarf Black hole red giant Supernova 10 Our sun has ______ billion year life span

62 Topic: Galaxies & The Big Bang Objectives: Day 4 of 4 I will be able to define a galaxy and classify the 3 different types of galaxies I will understand the Big Bang theory and the evidence supporting it Unit: Stars & Galaxies

63 Quickwrite: Answer one of the questions below in 1-2 sentences: Earth orbits the sun, but does our sun orbit anything???? How old do you think the universe is???? What sort of shape do you think the milky way galaxy has???

64 Galaxies We are on earth, all going around the sun However, does the sun orbit anything? The sun is one star among many in our Galaxy A galaxy is a group of billions of stars, gas and dust held together by gravity

65 Billions and Billions When we look out into deep space we see billions of galaxies Each galaxy contains billions of stars So space is made mostly up of star and galaxies

66 A galaxy is a group of billions of stars, gas and dust held together by gravity We classify galaxies into 4 types: Galaxies: 4 Types Elliptical: sphererical or oval shaped more common Irregular: small irregular shaped less common Barred spiral: same as spiral but has bar going through the middle of it Spiral: disc shaped, have long spiral arms

67 What is a Galaxy? A group of billions of ___, gas and dust held together by gravity 4 types: -Spiral: disc shaped, have long spiral arms -Barred spiral: same as spiral but with bar in the middle -Elliptical: most common, spherical or oval shaped -Irregular: least common, small irregular shaped Answer Bank 30,000 Red shift microwaves Stars 100,000 expansion

68 Milky Way Galaxy Contains around 500 billion stars The visible disk of stars is about 100,000 light years across The sun is located 30,000 light years out from its center All stars orbit around the central region Based on a distance of 30,000 light-years and a speed of 235 kilometers a second, the sun orbits around the center of the galaxy once every 240 million years

69 The Milky Way is usually classified as a spiral galaxy It is difficult to know for sure because it is impossible to see our galaxy from the outside You can see the Milky Way stretching across the night sky as a faint band of light All of the stars you can see in the night sky belong to the Milky Way Milky Way Continued…..

70 Our Sun is 1 star among 500 billion Our Milky Way galaxy is 100,000 light years across Our Sun and Solar System Is located 26,000 Light years form Our galactic center

71 What is the Milky Way Galaxy? A 10 billion year old barred spiral galaxy made up of around 500 billion stars and _____ light years across Our sun and solar system is located ____ light years from the center bulge Answer Bank 30,000 Red shift microwaves Stars 100,000 expansion

72 Big Bang Theory It is believed our billion our universe formed 10–20 billion years ago All matter existed in an incredibly hot dense state of hydrogen and helium After it exploded, it expanded & cooled into stars & galaxies

73 Big Bang Theory The big bang theory or model states that all matter in the universe was released in a massive expansion of time and space about billion years ago

74 Over Time Galaxies and stars continue to expand, moving farther apart and cooling in the process 13.7 billion years ago Time started when all Matter began to expand outward and fill an empty universe with stars and galaxies The Big Bang Theory

75 What is the Big Bang Theory or Model? Theory or model that states that all matter in the universe was released in a massive ____ of time and space billion years ago Answer Bank 30,000 Red shift microwaves Stars 100,000 expansion

76 Evidence for the Big Bang Theory Evidence for the big bang theory came through two huge pieces of evidence: Red Shift and cosmic background radiation in the form of radio waves and microwaves

77 Red Shift Red shift showed that all galaxies and stars are moving away from each other and in fact expanding If objects are expanding then at one point they must have been closer together Here’s how it works:

78 Background Radiation When Scientists look out into space, they detect cosmic background radiation left over from the Big Bang This radiation is just “drifting” in the background of space and is one of the reasons we get static on out TV’s and Radio’s

79 The Big Bang released high energy gamma waves Background Radio Waves & Microwaves As the universe expanded, high energy gamma waves became stretched out After 10 billion years, these waves stretched out even more, eventually becoming microwaves and radio waves These microwaves and radio waves makeup the background radiation scientists have detected drifting through space

80 What evidence supports the Big Bang Theory? Red shift from distant stars and galaxies Cosmic background radiation in the form of _______ and radiowaves Answer Bank 30,000 Red shift microwaves Stars 100,000 expansion

81 Summary A ___ is a group of billions of___, gas and dust held together by gravity We live in the ___ ___ which is _____ light years across ___ ____ and ____ radiation is evidence for the big bang & an expanding universe Our universe is ____ BYO (billion years old), our galaxy is ____ BYO Answer Bank Galaxy 13.7 Red shift microwaves Stars 100, Milky way


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