2Unit: Stars & Galaxies Topic: Our Sun Objectives: Day 1 of 4 I will learn the definition of a starI will learn the process of fusion in the sun’s coreI will be able to distinguish between the inner and outer layers of the sun
3Quickwrite: 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???
4Infrared Visible Light Ultra Violet X-Rays Gamma Rays Radio Waves &MicrowavesInfrared(heat)Visible LightUltra VioletX-RaysGamma RaysUltra Violet (UV) radiation from the Sun has an even shorter wavelength.UV Radiation is absorbed by the earth’s ozone layer & can cause skin cancerDue 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 injuryGamma Radiation has the shortest wavelengths of all radiationand is therefore Just small amounts can be fatal.Visible Light from the Sun has an even shorter wavelength.Light waves are the only type of radiation we can see.Infrared or heat waves have a shorter wavelength than radio waves.Heat Waves or radiation form the sun is what controls our weatherRadio Waves are given off by the Sun. These are long wavelengthwaves and create the static you get on your radios and TV’s
5What is a Star?A sphere of gases that produces heat and light through the ____ of hydrogenOur sun is average starAnswer BankstarsTransferCoolfusionphotosphere4
7Core 4 H = 1 He + energy Think Hydrogen Bomb! The core lies in the heart of the sun and is 15,600,000 degrees CelsiusThe nuclear process know as hydrogen fusion occurs in the coreDuring Hydrogen Fusion, 4 hydrogen combine to form 1 helium nucleus releasingtremendous amounts of energy4 H = 1 He + energyThink Hydrogen Bomb!
8The core, where nuclear fusion takes place let’s zoom in and In the Core, Pressures and Temperaturesare high enough for Fusion to take placeThe core, where nuclearfusion takes placelet’s zoom in andwhat happensHHHeHeHeHeHIn the process, energy is releasedin the form of light &radiationHFusion occurs when 4 hydrogen atoms (light element)combines to form 1 Helium atom (heavier element)Hydrogen, a lighter element is convertedinto a heavier element, helium
9What is Fusion?The combining of lighter elements to form heavier elementsIn 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 releasedAnswer BankstarsTransferCoolphotosphere4HHHHHHHHHeHeHeHeHeHeHeHeHeHeHeHeHeHeHeHeHHHHHHHH
10Radiative ZoneIn the radiative zone, energy moves radiates outward from the core in the form of light & radiationIt takes light thousands of years to move from the core to the next layerTemperature is 8,000,000 degrees Celsius
11Convection Zone Energy moves through this zone by convection Hot gases rise toward the surface while cooler gases sink back downIt’s behaves like a giant pot of boiling waterTemp = 2,000,000 degrees Celsius
17What are the Layer’s of the Sun? Core- produces energy from _______ FusionRadiative ZoneConvection ZonePhotosphere- gives off light, surface of the sunChromosphereCorona- seen during an_____, gives off solar windAnswer BankstarsTransferCoolhydrogen4eclipse
18Sunspots “Cool” dark areas on the Sun’s surface By studying sunspots, we have discovered that the Sun rotatesSunspots can last from a few days to a few monthsThey represent areas of intense Magnetic activity
19Sunspots “Cool” dark areas on the Sun’s surface By studying sunspots, we have discovered that the Sun rotatesSunspots can last from a few days to a few monthsThey represent areas of intense Magnetic activity
20Sunspot Cycle Maximums and Minimums Every 11 years our sun goes through a Sunspot cycleOur Sun has periods of sunspot maximums where many sunspots are visibleOur Sun also has periods of sunspot minimums where only a few sunspots are visible
21Solar FlaresA solar flare is a violent explosion in the Sun's atmosphereThey release tremendous amount of radiation or energy in the form of UV Rays, X-rays, and gamma rays
22ProminencesProminences are huge arching columns of gas on the surface of the sunThey erupt at speeds ranging from km/sUltraviolet light and x-rays from prominences can reach earth and cause disruption in radio signals
23What Features can be found on the Sun? Sunspots_____dark areas on the surface of the sun that occur in an 11 year cycle (maximums/minimums)ProminencesHuge arching columns of gasSolar Flaresviolent ____ of energy (radiation)Answer BankstarsTransferburstsCoolphotosphere4
24Summarize: Our sun is a star made mostly of ______ and helium gases _____ is the combining of lighter elements to form _____ elementsIn the Sun’s____, 4 hydrogen atoms a combine to form 1 ____ atom & energy is releasedAnswer BankheavierHydrogenfusionHeliumcore
25Topic: Light years & Stars Unit: Stars & GalaxiesTopic: Light years & StarsObjectives: Day 2 of 4I will understand the concept of a light year and how we use them to measure distances to Stars and galaxiesI will understand how stars vary in their size, color, temperature and brightnessI will learn how to classify stars on a H-R Diagram
26Quickwrite: 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????
27Light YearsWhen astronomers first realized how far away stars actually are, it became apparent that a new unit of measurement would be needed to record their distancesStars are much farther away than the planets in our solar systemDistances between stars are measured in light years!
28Light 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 galaxiesLight travels at 300,000 km/s or about9,500,000,000,000 trillion kilometers in one year (9.5 x 1012 km/yr) 299 ,792 km/ sNothing is faster than lightIf you travel at the speed of light, you would become light
29How Fast is That?A traveler, moving at the speed of light, would circum-navigate the equator approximately 7.5 times in one secondHow long do you think it takes light to reach Earth from the Sun?
30What 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/sLight years are used to measure very distant objects such as stars and galaxiesAnswer BankAverageTemperatureAbsoluteDistanceYear90%hot
31Parallax!How do we know the stars are farther away than the planets in our solar system? We use parallax!The distance of a star is found by using parallaxParallax is the apparent shift in the position of an object when viewed from two different positionsYou can easily observe parallaxHold your hand at arm’s length and look at one finger with your left eye and then with your right eyeWhat you will notice is that your finger appears to change position with respect to the background
32Parallax Continued…..Now try the same experiment with your finger closer to your faceWhat do you observe?The closer an object is to the observer, the greater its parallaxWe can measure parallax of relatively close stars in order to determine their distance from earth
35What is Parallax?Parallax is how we measure the ____ to stars in light yearsIt is found by viewing an object from 2 fixed locationsAnswer BankAverageTemperatureAbsoluteDistanceYear90%hot
36brightness & temperature Star CharacteristicsYellow Stars like areSun are average inbrightness & temperatureBlue Stars arelarge hot and brightRed Stars aresmall cool and dim
37What’s the relationship between star color, size, & temperature? Large Blue-white stars are ___ & brightRed stars are cool & dimYellow stars, like our sun are ____ in temperature and bright nessAnswer BankAverageTemperatureAbsoluteDistanceYear90%hot
38H-R DiagramIn the early 1900’s, Ejnar Hertzsprung and Henry Russell found a way to classify starsThey classified stars by their temperature and brightnessBlue Massive StarsSupergiantsGiantsSunHot White DwarfsRed DwarfsHot BrightBlue StarsCool RedDim StarsYellow OrangeAverage Stars
39H-R DiagramHertzsprung and Russell came up with a graph that shows the relationship between temperature and brightnessNotice where the cool small red dwarfs stars are locatedNotice where the massive hot blue dwarfs stars are locatedBlue Massive StarsSupergiantsGiantsSunHot White DwarfsRed DwarfsHot BrightBlue StarsCool RedDim StarsYellow OrangeAverage Stars
40What is the H-R Diagram?A graph that compares the brightness, ______ and color of a star_____ magnitude is the true brightness of a starAnswer BankAverageTemperatureAbsoluteDistanceYear90%hot
41Main 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 cornerMain Sequence Stars contain large, hot blue stars, as well as small cool red stars90 % of all stars are Main SequenceBlue Massive StarsSunRed DwarfsHot BrightBlue StarsCool RedDim StarsYellow OrangeAverage Stars
42What are Main Sequence Stars? The diagonal band of stars in an H-R diagramBlue, white, yellow, orange, red stars____ of the stars we see at night are main sequenceAnswer BankAverageTemperatureAbsoluteDistanceYear90%hot
43Summarize:_______ is how we measure star distances when viewed from two fixed locations as we orbit the sunLarge stars are ____ and small stars are ____Hot stars are ______ in colorCooler stars are ______in colorAn H-R diagram is a graph that relates star ________ to star ________Answer BankBrightnesstemperatureParallaxbrightAbsolutebluereddim
44Unit: Stars & Galaxies 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 sunTo understand how nucleosynthesis occurs in starsStar size:
45Quickwrite: 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????
46Star Size But what determines the size of a star? All star’s form in a nebulaA star will begin it’s main sequence when hydrogen fusion beginsBut what determines the size of a star?Gravity wants to crush the starSo why doesn’t it?Because the outward pressureOr force of energy fromFusion balances out theinward force of gravityThis keeps the star in astate of balance or equilibrium!
47What determines the size of a main sequence star? A balance between the ____ pull of gravity and the outward push of energy created by fusionAnswer BankNeutronLighterInwardRedFusionWhite dwarfshort
48Temperature & Pressure Affect Star Life HydrogenTemperature & Pressure Affect Star LifeEmpty FullHydrogenLarge massiveblue stars haveShort livesBecause they havehigher pressures &temperatures in theCore, therefore theyrun through theirHydrogen fuelsource fasterHydrogenEmpty FullStar like oursun haveaverage livesEmpty FullSmall Red dwarfstars have long livesbecause of coolertemperaturesin the core
49How does temperature and pressure effect the life of a star? Temperature and pressure increase the rate of fusion in a stars coreHot blue stars have ____ livesCooler ___ stars have long livesYellow stars like our sun have average livesAnswer BankNeutronLighterInwardRedFusionWhite dwarfshort
50Massive Blue Star Lifecycle In a massive blue stars core, hydrogen fusestogether to form Helium for most of itsshort Main sequence lifeEventually hydrogen startsto run out and heliumstarts to accumulateAs a result gravity wantsto crush the star, pressures &temperatures increase, & the starbegins fusing helium into carbonCarbonHeliumHeliumOver time the outward pressure orforce of energy from fusion becomesstronger than the inward force of gravity &the star begins to swell & cool changing its color in the process
51Massive Blue Star Lifecycle Temperatures continue toincrease in the core, & thestar begins fusing Carboninto OxygenAt this point the staris now a supergiantCarbonHeliumOxygenCarbonHeliumHydrogenBut fusion doesn’t stopJust yet!!!!!
52Massive Blue Star Lifecycle Finally, as temperatures continue to increase thestar will begin fusing oxygen into IronNear the end of it’s lifeThe blue massive starresembles an onion withlayers of different elementsCarbonHeliumIronOxygenCarbonOxygenCarbonHeliumHydrogenThis process is calledNucleosynthesis—WhereLighter are elements are createdinto heavier elements throughFusion in a starHeliumHydrogen
53Massive Blue Star Lifecycle In massive blue starsElements up to the size ofIron-element 26 are createdThrough fusionCarbonHeliumIronOxygenCarbonOxygenCarbonHeliumHydrogenHelium
54Massive Blue Star Lifecycle At a certain temperature, Fusion can no longeroccur and the outward energy stops,at this point gravity takesOver and crushes the starBlack HoleNeutron StarThe star explodesinto a super nova!!!CarbonHeliumIronOxygenCarbonDepending upon the starsinitial mass or size, It will end upas either a neutron star or Black holeHeliumHydrogen
55Massive Blue Star Lifecycle When the star explodes, it blasts all The elementsinto space, seeding the universe with Elementsto make new stars, planets, people and buildingsSupernovas are so hot & bright, They produceall other elements heavier than ironCarbonHeliumIronOxygenCarbonHeliumHydrogen
56What 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 supernovaWhen a super giant star goes supernova (explodes) it creates elements _____than Iron such as gold and leadAnswer BankNeutronLighterInwardRedIronheaviershort
57Yellow Star (Sun) Star Lifecycle Our sun’s core will fuse hydrogen intoHelium for most of its 10 billionyear old Main sequence lifeThroughout this time HeliumWill accumulate in its coreHeliumCarbonHeliumCarbonHeliumAs a result of gravitycrushing the star, pressures& temperatures increase & thestar begins fusing helium into carbonHeliumOver time the outward pressure or force of energy from fusionbecomes stronger than the inward force of gravity & the starbegins to swell & cool changing its color in the process
58Yellow Star (Sun) Star Lifecycle Temperatures continue toincrease in the core, & thestar begins fusing Carboninto OxygenAt this point the staris now a Red GiantCarbonHeliumHeliumOxygenCarbonHeliumHydrogenUnlike a blue star, temperaturesand pressure are not high enoughTo produce Iron through fusionFusion stops at OXYGEN
59Yellow Star (Sun) Star Lifecycle Instabilities in thebalance BetweenGravity & outwardforce or Pressureof fusion result inabrupt explosionsthat blow awaythe outer layersof the starCarbonHeliumHeliumOxygenCarbonHeliumHydrogenThe result is aplanetary nebulawith a hot whitedwarf star in the middle
60Yellow Star (Sun) Star Lifecycle Eventually theGases are expelledLeaving behindA white dwarf starA white dwarfstar is what remainsof an average starlike our sun afterRunning out of fuelIt’s aboutthe size of earth
61Summarize: ???? ???? Our sun has ______ billion year life span ???? Answer BankWhite dwarfBlack holered giantSupernova10????Our sun has ______ billion year life span
62Topic: Galaxies & The Big Bang Unit: Stars & GalaxiesTopic: Galaxies & The Big BangObjectives: Day 4 of 4I will be able to define a galaxy and classify the 3 different types of galaxiesI will understand the Big Bang theory and the evidence supporting it
63Quickwrite: 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???
64Galaxies We are on earth, all going around the sun However, does the sun orbit anything?The sun is one star among many in our GalaxyA galaxy is a group of billions of stars, gas and dust held together by gravity
65Billions and BillionsWhen we look out into deep space we see billions of galaxiesEach galaxy contains billions of starsSo space is made mostly up of star and galaxies
66Galaxies: 4 TypesA galaxy is a group of billions of stars, gas and dust held together by gravityWe classify galaxies into 4 types:Elliptical: sphererical or oval shaped more commonIrregular: small irregular shaped lesscommonSpiral: disc shaped, have long spiral armsBarred spiral: same as spiral but hasbar going through the middle of it
67What is a Galaxy?A group of billions of ___, gas and dust held together by gravity4 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 shapedAnswer Bank30,000Red shiftmicrowavesStars100,000expansion
68Milky Way Galaxy Contains around 500 billion stars The visible disk of stars is about 100,000 light years acrossThe sun is located 30,000 light years out from its centerAll stars orbit around the central regionBased 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
69Milky Way Continued…..The Milky Way is usually classified as a spiral galaxyIt is difficult to know for sure because it is impossible to see our galaxy from the outsideYou can see the Milky Way stretching across the night sky as a faint band of lightAll of the stars you can see in the night sky belong to the Milky Way
70Our Sun is 1 star among 500 billion Our Milky Way galaxy is 100,000 Our Sun andSolar SystemIs located 26,000Light years formOur galactic centerOur Milky Waygalaxy is 100,000light years acrossOur Sunis 1 staramong500 billion
71What is the Milky Way Galaxy? A 10 billion year old barred spiral galaxy made up of around 500 billion stars and _____ light years acrossOur sun and solar system is located ____ light years from the center bulgeAnswer Bank30,000Red shiftmicrowavesStars100,000expansion
72Big Bang TheoryIt is believed our billion our universe formed 10–20 billion years agoAll matter existed in an incredibly hot dense state of hydrogen and heliumAfter it exploded, it expanded & cooled into stars & galaxies
73Big Bang TheoryThe 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
74The Big Bang Theory Over Time 13.7 billion years ago Galaxies and stars continueto expand, moving farther apartand cooling in the process13.7 billion years agoTime started when all Matterbegan to expand outwardand fill an empty universewith stars and galaxies
75What 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 agoAnswer Bank30,000Red shiftmicrowavesStars100,000expansion
76Evidence 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
77Red ShiftRed shift showed that all galaxies and stars are moving away from each other and in fact expandingIf objects are expanding then at one point they must have been closer togetherHere’s how it works:
78Background RadiationWhen Scientists look out into space, they detect cosmic background radiation left over from the Big BangThis 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
79Background Radio Waves & Microwaves The Big Bang releasedhigh energy gamma wavesAs the universe expanded,high energy gamma wavesbecame stretched outThese microwaves and radio wavesmakeup the background radiation scientistshave detected drifting through spaceAfter 10 billion years, thesewaves stretched out evenmore, eventually becomingmicrowaves and radio waves
80What evidence supports the Big Bang Theory? Red shift from distant stars and galaxiesCosmic background radiation in the form of _______ and radiowavesAnswer Bank30,000Red shiftmicrowavesStars100,000expansion
81SummaryA ___ is a group of billions of___, gas and dust held together by gravityWe live in the ___ ___ which is _____ light years across___ ____ and ____ radiation is evidence for the big bang & an expanding universeOur universe is ____ BYO (billion years old), our galaxy is ____ BYOAnswer BankGalaxy13.7Red shiftmicrowavesStars100,00010Milky way