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Name ________________________ BLACK HOLES ACTIVITY 1. Go to: http://www.pbs.org/wnet/hawking/strange/html/strange_exist.html and give two examples that black holes do exist. 2. Look at this chart: http://www.pbs.org/wnet/hawking/strange/html/strange_blackh.html a) A massive star starts to __________________ when it exhaust its nuclear fuel and can no longer counteract the inward pull of _________. b) The crushing weight of the star's overlying layers implodes the ___________, and the star digs _________________ into the fabric of space-time. c) Although the star remains barely visible, its ___________ now has a difficult time climbing out of the enormous ____________ of the still-collapsing core. d) The star passes through its event horizon and _____________ from our universe, forming a singularity of infinite ______________. 3. Go to this link: http://www.pbs.org/wnet/hawking/strange/html/strange_escape.html Can anything escape from a black hole? Name ________________________ Virtual Experiment Build Your Own Star http://www.seed.slb.com/en/scictr/lab/byo_star/index.htm 1. What are the two main factors that determine how the life of a star unfolds? a. _______________________________________ b. _______________________________________ 2. What are the two elements that are not referred to as metals by astronomers? _________________, _________________ 3. If you set the metal to .001, what percentage of metals will the star be? _______________ 4. On the H-R Diagram, where are stars hottest? _____________________________________, What is the highest temperature value? ________________________ 5. For each stage, summarize the description of each star stage a. Protostar ______________________________________________________________________ b. Main Sequence _________________________________________________________________ c. Hertzsprung Gap _______________________________________________________________ d. Naked Helium Star _____________________________________________________________ e. Core Helium Burning ___________________________________________________________ f. Carbon/Oxygen White Dwarf _____________________________________________________ g. Neutron Star __________________________________________________________________ h. Black Hole ____________________________________________________________________ Virtual Experiment 1. What would the mass and metal levels be to match out own Sun? Mass _______ Metal _________ Run the experiment at those levels a. How long will our Sun be a Main Sequence star? ____________ b. What will the next stage be, how long does it last? ___________________, _________________ c. What occurs next? ____________________________ d. What is the final stage of our Sun, how old is it? _________________, ____________________ 2. How long does a star that is 10x more massive (same metal ratio) than the Sun stay on the main sequence? ___________________ 3. Calculate the % the age of the higher mass stars in question #2 would represent vs. our Sun’s life as a main sequence, question #1a (Show you work) 4. How long does a star that is 25x larger and our Sun stay on the Main Sequence? _________________________________ 5. How does a star’s life with the same mass as our Sun change when you decrease the metal content to .001? ____________________________________________________________ 6. What are the radius of the objects below? a. Main Sequence (mass 1, metal .02) ___________________________ b. Hertzsprung Gap (mass 1, metal .02) __________________________ c. First Asymptotic Giant Branch (mass 1, metal .02) ________________________ d. Carbon/Oxygen White Dwarf (mass 1, metal .02) _________________________ e. Neutron Star _______________________________________ f. Black Hole _________________________________________ 7. Calculate how much larger the radius of a star that is 100 times more massive than the Sun would be both main sequence stage. (show work) 8. Calculate how much larger the radius of a main sequence Sun compared to a white dwarf. (show work) 9. What is the brightest object you can create, describe the mass, metal and stage and luminosity.? 10. What is the largest object you can create by radius, describe the mass, metal and stage? 11. What effects the life of a star more, metal content or mass? Explain your answer Name_________________________ Period___________ Date___________ Partner_________________________ Topic V: Energy in Earth Processes LAB 5-1: ELECTROMAGNETIC SPECTRUM INTRODUCTION: Light comes to us through the vacuum of space, from the sun in the form of electromagnetic waves. All matter will radiate electromagnetic energy unless it is at a temperature of absolute zero OBJECTIVE: You will observe the spectrograms of several light sources and describe how they are different. VOCABULARY Spectrum: Radiation: Vacuum Wavelength: Frequency: Absolute Zero: Absorption: PROCEDURE: 1. Using a spectroscope, observe the bright sky. NEVER LOOK DIRECTLY AT THE SUN. In box #1 on your Report Sheet, using colored pencils, draw a spectrogram of what you see. 2. Observe the spectra from the gas tube sources supplied by your instructor. Draw and label the spectrograms in the appropriate boxes on your Report Sheet. Drawing Spectra Element _______________________ Element _______________________ Element _______________________ Element _______________________ Element _______________________ Element _______________________ Element _______________________ Element _______________________ Element _______________________ Element _______________________ Element _______________________ Element _______________________ Discussion Questions 1. List the colors of the visible portion of the electromagnetic spectrum in order from long wave to short wave. 2. What is the difference between the spectrum of the Sun and that of the light bulb? 3. What is the difference between the spectrum of the light bulb and the spectra of the gas tubes? 4. Refer to the spectra of the gas tubes. How is possible to identify an element by looking at its spectrum? For Questions 5-9, refer to the chart “Electromagnetic Spectrum” on pages 97 and 115. 5. As the frequency of an electromagnetic wave increases, what happens to the wavelength? 6. How does the width of the visible spectrum compare to that of the entire electromagnetic spectrum? 7. How does the wavelength of the infrared portion of the electromagnetic spectrum differ from that of the visible portion of the spectrum? 8. For each wavelength region, what would be the best location to study object in that wavelength? X-rayUVVisible- Infrared- Radio- NAME CLASS _ ~ DATE _ Lab: Properties of Stars The Hertzsprung-Russell diagram, or H-R diagram, is a graph in which a star's tempera ture is plotted against its absolute magnitude. From such a diagram, other information about a star's properties and life cycle can be determined. A simplified H-R diagram appears in your textbook IFigure 21.6, page 3821. In this laboratory, you will construct an H-R diagram using data on the 20 stars that are nearest to our sun (Figure 21.11 and the 20 stars that appear brightest in our sky (Figure 21.21.Then you will use the finished dia gram to describe the properties and life cycles of stars. In the tables in Figures 21.1 and 21.2, the unit used for distance is the parsec. A parsec is equal to 3.26 light-years ILYI. The Kelvin (KI, or absolute temperature scale, is used in the tables and in the diagram (Figure 21.3). . , Objectives • • • • To graph a simplified Hertzsprung-Russell diagram To identify the characteristics of a star from data in the diagram To classify a star by its position in the diagram To compare the life cycle stages of stars based on their positions in the diagram Materials • • • • data for nearest and brightest stars (Laboratory 21 Figures 21.1, 21.21 graph (Laboratory 21 Figure 21.3) sample Hertzsprung-Russell diagram (textbook Figure 21.6, page 382) pencil .. , .Procedure I. Study the lists in Figures 21.1 and 21.2 and answer Analysis and Conclusions ques tions 1 and 2. In procedure steps 2 and 3, you will graph the stars onto the diagram. The following tips will be helpful to remember when graphing stars: a. Temperature is on the horizontal axis; absolute magnitude is on the vertical axis. b. Notice that the graph lines used to plot temperature are unevenly spaced, and that the number of Kelvins between each line is not constant. Carefully check a star's tem perature and the value of a particular graph line before plotting each star. c. Absolute magnitude decreases .as the value becomes more positive. Thus, an absolute magnitude of +4.4 plots below the +4.0 line, not above. 2. Using a plus sign (+), graph each of the nearest stars (listed in Figure 21.1) on the dia gram (Figure 21.3). 3. Using a circled dot IG»), graph each of the brightest stars as seen from Earth (listed in Figure 21.2) on the diagram. Show stars that appear on both tables using a circled plus sign (8). 4. Answer Analysis and Conclusions questions 3-10. The 20 Brightl·.,t Star, a, The 20 Nearest Star., Distance Temperature Absolute (K) Magnitude (parsecs) Name Name SCl'IlIWIll I.urt h Distance Temperature Absolute (parsecs) (Kr Magaitade 2.7 10400 +1.4 30.0 7400 -3.1 1.3 5800 +4.4 11.0 4500 -{l.3 8.0 10 700 +0.5 14.0 5900 -{l.7 250.0 11800 -6.8 3.5 6800 +2.7 Betelgeuse 150.0 3200 -5.5 +13.5 Achernar 20.0 14000 -1.0 2700 +14.9 Beta Centauri 90.0 21000 -4.1 3.40 2800 +7.5 Altair 5.1 8000 +2.2 Procyon 3.47 . 6800 +2.7 Alpha Crucis 120.0 21000 -4.0 Epsilon Indi 3.51 4200 +7.0 Aldebaran 16.0 4200 -o.z Sigma 2398 3.60 3000 +11.1 Spica 80.0 21000 -3.6 BD+43°44 3.60 3200 +10.3 Antares 120.0 3400 -4.5 Tau Ceti , 3.64 5200 +5.7 Pollux 12.0 4900 +0.8 CD -36 ·3.66 3100 +9.6 Fomalhaut 7.0 9500 +2.0 RD +SOj(-i(-iR 3.76 3000 +11.9 Deneb 430.0 9900 -6.9 CD-39°14192 3.92 3500 +8.7 Beta Crucis 150.0 22000 . -4.6 Sirius Alpha Centauri 1.31 5800 +4.4 Barnard's Star 1.83 : 2800 +13.2 Canopus Wolf 359 2.35 2700 +16.8 Alpha Centauri Lalande 21185 2.49 3200 +10.5 Arcturus Sirius 2.67 10400 +1.4 Luyten 726-8 2.67 2700 +15.4 Capella Ross 154 2.94 2800 +13.3 Rigel Ross 248 3.16 2700 +14.7 Procyon Epsilon Eridani 3.30 -1-500 + 6.1 Ross 128 3.37 2800 Luyten 789-6 3.3.7 61 Cygni 015693 Figure 21.1 Analysis and Conclusions Vega Figure 21.2. I. Compare the two star lists, Figures 21.1 and 21.2. How many stars appear on both the Nearest Stars list and the Brightest Stars as Seen from Earth list? Name them. . 2. What does your mswer to question 1 indicate about the nearest stars? .Are the nearest stars also the brightest stars as seen from Earth? i , , , i , i i +9 , +10 + 11 i i +12 +13 +14 , , +15 , , +16 , i , , +17 o o o ~ i , o o o o o o o 0'> co o o o o o or-... Temperature (K) o o o co o o oIi) o o o 'T o o o C"l 8 C\I NAME ClASS· DATE _ ·3. A star located in the lower right portion of Figure 21.3 is cool and dim. What are the characteristics of a star in the upper left of the diagram? In the upper right? 4. Refer to Figure 21.6 on Page382 of your textbook. To which group do most of the stars on your diagram belong? 5. According to your diagram and Figure 21.6, are any of the 20 nearest or 20 brightest stars white dwarf stars? What is the evidence for your answer? 6. Our sun has a temperature of 6000 K and an absolute magnitude of +4.7. Use an asterisk I * I to show the location of the sun on your diagram. To what group does the sun ~~ 7. Compare the absolute magnitude and temperature of the sun with those of the other stars in its group. 8. Betelgeuse is 150 parsecs away and has a surface temperature of only 3200 K. Yet Betelgeuse is one of the brightest stars as seen from Earth. What does this indicate about the size of Betelgeuse? Is your answer supported by the location of Betelgeuse on the diagram? 9. On your diagram, there is another star that is plotted near Betelgeuse. What is the name of the star? What kind of star is it? I o. Compare our sun with the red supergiant Antares. Which star is further along in its life cycle? How do you know? Name: ___________________________ Date: ___________________________ Spectroscopy of Stars and Galaxies Objective: Spectroscopy is the science of looking at rainbows. By splitting starlight into its different wavelengths, or colors, we can learn a great deal. By measuring the wavelengths and strengths of absorption and emission lines seen in a star’s spectrum, we can tell what it is made of, how hot it is, and how fast it is moving. In this lab you will examine the spectra of a few elements and compare them with some spectra of stars and galaxies taken by astronomers. In this way we can learn what is going on in atoms that are millions of light years away. Exercises: A. Using figure 3.5 on page 97 in your text, make a complex visible spectrum on the scale provided. B. On the next page you will find the emission spectra of hydrogen, helium, mercury and neon and the absorption spectra of a star from a distant galaxy. At this point, you should color the specific wavelengths according to the spectrum that you completed above. C. Suppose that you have just used an advanced spectroscope to examine a distant star. Using the spectroscope you observed radiation at the following wavelengths: 660nm, 480 nm, 430 nm and 410 nm. Using this information complete the emission spectrum below for the distant star. Hydrogen Helium Mercury Neon Spectrum of a bright star in a distant galaxy: 1. What is the probable source of this radiation? In other words, what type of gas is emitting this radiation? Refer to the bright star in a distant galaxy spectrum. D. Suppose you observed the following wavelengths: 700 nm, 690 nm, 642 nm, 628 nm, 620 nm, 585 nm, 580 nm, 534 nm and 470 nm. Use this information to reconstruct this star’s emission spectrum. 2. What is the probable source of this radiation? E. Look at the imaginary spectrum of “a bright star in a distant galaxy,” at the bottom of the previous page. Compare the pattern of absorption lines in this spectrum with the emission lines in the spectra of hydrogen, helium, mercury and neon, 3. What are the wavelengths of the lines shown? 4. From the pattern of lines, what would you say is the most prominent element in this star? 1 Astronomy Student Notes Our Sun and Other Stars Name __________________ Date _________ Period ________ Vocabulary: Please number and define each term below in a complete sentence on a separate sheet of paper(terms that have an *, please illustrate) Photosphere* Chromosphere* Red Dwarfs Blue Supergiants Corona * Convection Zone* Solar Core* Radiation Zone* Standard Solar Model Helioseismology* Granulated Supergranulation Transition Zone Solar Wind* Sunspots* Sunspot Cycle Solar Minimum* Solar Maximum* Solar Cycle Active Regions Prominences* Flares Parsec* Giants Supergiants Red Giants* Dwarfs White Dwarfs* Color Index* H-R Diagram* Main Sequence* The Sun in Bulk A.How does the text describe the structure of the Sun? -the Sun is __________ sized, temperature, mass, radius and composition, making it easy for life to flourish on ____________ B.What happens in each layer of the Sun? -_______________- where nuclear fusion takes place which powers the Sun, found at the center -________________- located outside the core, it transfers energy from the core by radiation -_________________- material from the radiation zone is transferred by convection instead of radiation -________________- considered the surface of the Sun, always a gas state, just like every other layer -_____________________- the Sun’s lower atmosphere -___________- the very thin outer atmosphere of the Sun, visible during a total eclipse -____________________- energy flows out from the Sun and permeates the entire solar system C.How big is the Sun compared to Earth in diameter and radius? -The Sun is about 100 times the diameter of the Earth and has a volume _____________ times of Earth -The mass of the Sun is about _______________ times greater due to the effect on all object in the solar system D.How long does one rotation take place on the Sun, (at the Equator, at the Poles)? - The Sun rotates once every 27 days at the equator and 31 days at the poles E.What is the average solar surface temperature in Kelvin (Fahrenheit)? - The solar surface averages 5800-6000 _____________ in temperature F.What is luminosity, how much energy does the Sun give off each second? -Every second the Sun gives off the equivalent of energy to 100 billion megaton __________________ The Solar Interior A.What is ______________________, how is information in this field of science gathered? -Study of the interior of the Sun (has nothing to do with seismic waves and earthquakes) - Using computer models, physics and estimates, scientists have determined the ____________ and temperature of the internal layers of the Sun B.What is convection, how does it work on the Sun? -In the convection layer ___________ is transported to the upper levels through convection (same way that a pot of water begin to rise in temperature) 2 -The gas particles in the core and radiation zone ____________ with each other constantly but by the time it get to 200,000 km out it is turned into energy and through convection transferred towards the surface C.What is Granulation? -Looking at the surface of the Sun it looks highly ________________ -Each granule is about 1000 km across, has a lifetime of __________________ and depending on its color light or dark will fluctuate in temperature by 500 K -Granules shows ____________________ rising up to the Photosphere The Solar Atmosphere 1.What is the composition of the Sun’s atmosphere? - by studying the absorption lines, from the photosphere ________________ can be found, hydrogen and helium are the most abundant elements, just like on the Jovian planets 2.When is the Chromosphere and Corona visible? -Chromosphere- not visible unless a ___________________ is occurring, sight of solar storms -which layer is hotter, why? Corona - spectral lines are dramatically different due to ____________________, temperatures dramatically increases above the chromosphere in the transition zone for reasons that are still not entirely known 3.What is the Solar Wind? - radiation moves away from the Sun at the speed _______________, and particles such as protons and electrons escape at ___________________ -The Sun in X Rays- gas emitted at _____________________ cannot be seen by regular telescope but by x ray telescopes, can detect coronal holes where the solar wind escapes F.The Active Sun 1.What is the difference between the active Sun and quiet Sun? - Continuous emission from the Sun’s photosphere gives off the luminosity, this is ordinary and called the quiet Sun, while unpredictable radiation that affects us on Earth is called the ___________________________ 2.What are sunspots, what causes them? -Dark spots on the Sun that are ______________________ of the photosphere - ______________________- the cause of sunspots, the magnetic fields tend to be 1000 times greater than the surrounding hotter photosphere, usually pairing up with another sunspot with the same polarity 3.What is the Solar Cycle? - a sunspot cycle lasts approximately ___________ (# of sunspots reaches maximum) due to the 22 year cycle of the Sun’s magnetic field which is stretched due to the differential rotation and convection at different latitudes 4.What happens at active regions- during solar maximum? -During solar maximum (11 year cycle), large ______________________ of energetic particles erupt violently from the photosphere then arch back towards the sun due to the magnetic field, releasing more energy than all the power plants on Earth producing energy for 1 billion years) G.The Heart of the Sun 1.How much energy is generated through solar energy production on the Sun? - The amount of energy released by the Sun daily dwarfs the energy released from solar prominences and flares, each kilogram of solar material (2.5 lbs), thirty trillion joules of energy must arise, the only way to produce this much energy is by ______________________ (combining of light nuclei into heavier ones) -What is nuclear fusion (in about 2 sentences)? 3 -Fusing of 2 _______________________ nuclei= tremendous release of energy and a third atom of helium, this is called the proton-proton chain -Sun fuses ________________________ of material per second, very little mass is lost in the Sun, most is just converted into another element -Why is observation of Solar Neutrinos important? - Astronomers cannot witness nuclear fusion in the core of the Sun, but indirectly detect it through _______________________ (byproduct of nuclear fusion) -Solar neutrino detectors are built deep within the Earth where only neutrino can penetrate and react with chlorine to make argon, they haven’t found the amount of neutrinos expected, why? The Distances to other Stars -How is stellar parallax used? -A stars apparent shift relative to some more distant background as the observer’s point of view change -Using the _________________________, astronomers can use two ends of a baseline, or two opposites sides of the Earth, for more distant stars using parallax requires using the Earth’s different positions at different points of the year (up to 2 A.U. for a baseline) -What distance do we used to find distance, what is the length? -Using parallax to find distance is measured in parsecs (pc), 1 parsec= ____________________ -How many star are in our neighborhood (within 4 pc), which is the closest? -approximately ______________ lie within 4 pc (13.2 light years) of Earth, the closest star is called Proxima Centauri at 4.3 light years away or 270,000 A.U. -How many stars are within 100 light years of Earth? -1000 stars are within _____________________ of Earth but most are well beyond this distance Stellar Temperatures How do we measure a Star’s temperature? -By measuring app. Brightness and the __________________________ (frequency of radiation emitted by a hot object) a stars temp. can be determined What is the color index? -By color we can approximate a star’s surface temp. __________________= 30,000 Kelvin ____________= 3,000 K Stellar Sizes How do we determine the radius of other stars? -Using Geometry, astronomers can directly measure the sizes of a few nearby stars but for most stars, astronomers know how to determine a star’s ___________________________ and from this the radius of the star can be determined ex. The Star Mira has a surface temperature of 3,000 K and a luminosity of 1.6x 1029 Watts= 80 times the radius of Sun -What makes a star a Giant? -stars with radii of _______________ that of our Sun -What makes a star a Supergiant? - even larger stars with radii of up to _____________ times of our Sun -What makes a star a Red Giant? - a giant star with a temperature of ______________ -What makes a star a Dwarf - stars that are smaller than the Sun, some similar to the size of _________________, most dwarfs are very hot at 24,000 K, __________________ is a white Dwarf Luminosity and Brightness -What is the difference between apparent brightness and absolute brightness? 4 -Apparent brightness is the amount of luminosity from a star as seen from Earth, not a true measure of luminosity, the formula is: -How do we determine the apparent brightness? - Absolute brightness = ___________________________ Temperature and Color -What are two ways that we can determine the temperature of a star? - By looking at the _________________ of a star, a rough estimate on temperature can be determined but with at least one intensity measurement at different wavelengths the exact temperature can be determined -________________________ is the second way -What is photometry - analysis in which a star’s intensity is measured through a set of standard filter The Classification of Stars -How do we classify stars? - Using a ____________________of temperature, color, spectroscopy and spectral-line radiation are all used to classify stars -What does a detailed spectra tell us? - looking at various stars’ spectrums, which shows different elements appearing (though they all have similar elemental abundances) due to different temperature of stars -How are stars classified? - stars are classified based on _________________________________, the hottest stars are an O to M being the coolest: __________________________________________ Further subclasses of stars are numbers, our sun is G2 star, not quite hot enough to be considered a G1 but hotter than a G3 The Hertzsprung-Russell Diagram -How are stars classified on H-R Diagrams?, -A star’s luminosity (__________________________________) and its surface temperature (spectral class or color) are used to classify it -Who invented it? -in the _______________ Ejnar Hertzsprung and Henry Russell plotted these two qualities to come of with the H-R Diagram -What is on the x-axis, y-axis? - Surface temperature is on the ____________ while _________________ is on the y-axis, the Sun is right in the middle -What is the main sequence? - The main sequence- Hertzsprung and Russell noticed that most stars fall in certain sections, cool stars tend to be faint while bright stars tend to be hot -_________ of stars are probably main sequence stars, while the remaining 9% are white dwarfs and 1% are ________________ Extending The Cosmic Distance Scale -What method is used to find the distance to stars beyond 100 pc? - Using ________________________________ is a method for determining distance to stars beyond 100 pc, this measurement is based on the H-R Diagram reading and the assumption that stars far away are probably similar to the one within 100 pc, this measurement is probably only 25% accurate Stellar Mass -How do we determine the mass of other stars? 5 -luminosity class considers density of __________________________ which determines between a bright giant and a supergiant -What are binary-star systems? -two stars that are part of the same solar system we can see them __________________ -Why are eclipsing binaries helpful in studying star features? - binary stars eclipse each other and are called eclipsing binaries, the light difference is measured and can determine __________________________________________ -What determines the location of a star on the main sequence? -The mass of a star determines its location on the ________________________, the radius of a star rises in proportion to its mass, while luminosity rises more like the cube of its mass -How long do different stars live for? -Stellar mass/Stellar Luminosity, large O and B stars that are 10-20 times more massive than the Sun and 1000’s of times more luminous usually die out within 20 million years, M stars are much less massive and very faint but will exist for ______________________, while K and over a trillion years Chapter 20 Stellar Evolution -What happens to an aging G type main sequence star? -Its core temperature slowly increases due to consumption of Hydrogen converted to ______________ -Towards the end of its 10 billion year life, our Sun will change its appearance and its days are numbered (low mass stars die gently while high mass stars die catastrophically) -When all H is gone a star gets brighter and over 100 million years grows to a red giant and moves to the cooler position on the HR Diagram -The Sun grows to 8 times the mass of the Sun- (considered a high mass star) -What happens when the core becomes all Helium? -The Helium shell flashes causes it to be unstable, causing the outer layers to pulsate eventually becoming a planetary nebula -After many Helium flashes a white dwarf appears in a few thousand years (very hot- about the size of Earth but a mass of ½ the Sun) 20.4 Evolution of Stars more Massive than the Sun -How will a more massive Star differ in its death? -High mass stars evolve much faster than low mass stars -Our Sun will spend 10 Bill. Years on the main sequence -5x solar mass (B stars)- only 100,000,000 years on Main Seq. -10 x solar mass (O stars)- only 20,000,000 years on “ “ -Stars leave main sequence for one basic reason- run out of H -A high mass star > 8 solar masses are able to fuse heavier and heavier elements Chapter 21 Stellar Explosions -What happens when a high mass star’s core fuses completely into Iron? -The star implodes falling in on itself, the temperature rises to ___________________ -The spectacular death rattle of a high mass star is known as a ________________________ -What is a Type I supernovae? -Hydrogen poor, resulting from a carbon white dwarf (descendant of a low mass star) pulling matter from binary nearby ____________________________ What is a Type II supernovae? -Hydrogen rich, results of a high mass star core collapse How do we know Supernovae occur? -Supernova remnants in our galaxy- ______________________ 6 -Originally exploded in 1054 AD, brighter than Venus and visible during the daytime -From supernovae, all elements found on the ___________________ are created Chapter 22 Neutron Stars and Black Holes What is left after a star goes supernova? -The core remnant is called a _________________, they are extremely small (size of a large city) but very massive (more massive than the Sun), a billion times denser than a white dwarf ex. Half a teaspoon of neutron star would weigh _____________________ (as much as an 8,000 ft mountain) Neutron stars are solid but if you walked on one you would weigh 1 billion tons and be flatten thinner than a piece of paper How can we detect neutron stars? -Neutron stars rotate in _______________________, they are referred to as Pulsars- emitting periodic bursts of radiation like a lighthouse flashing between 3-30 times/second 22.5 Black Holes How massive does a star need to be to become a black hole? -Any star with a mass of ____________, the central core collapses forever creating a black hole -At this point gravity is so strong not even light, radiation and information can escape -___________________ mechanics cannot explain the conditions created in or near a black hole What is the escape speed of a black hole? -Remember: Escape speed is proportional to the square root of a body’s mass by the square root of its radius -Earth’s escape velocity is _______________, if Earth were compressed to ¼ it size, escape speed= 22 km/s -If we compress Earth to about a _____________________= 300,000 km/s escape speed (speed of light), this would mean nothing can escape the speed of gravity How does a black hole affect surrounding space? -Any object with a lot of mass curves space (the actual fabric), the more massive the object the more space surrounding it is __________________ -If an object is massive enough (> 25 solar masses) it will create an Event Horizon -Over time a black hole’s mass grows when debris come into the vicinity of the event horizon What if we could send an astronaut into a black hole, what would it be like? -If an astronaut tried to travel towards a Black Hole he/she would be squeezed and stretch unmercifully, they would also be heated to extremely ____________________________ What if we could send an impenetrable probe to extreme environments (no such thing for a black hole) into a BH? -If we could send a probe, while we observe from a safe distance, we would see the green light from the robot become ___________________________ to gravitational redshift -The robots clock signal would tick _________________ than an equivalent clock on board our space ship, till it stops altogether, this is called _____________________ -To the in-falling probe time would remain the same -If the probe made it past the Event Horizon, what would happen? No one knows! Humans need to develop a better overall theory of _________________ (quantum gravity- the merger of general relativity with quantum mechanics) -_________________ attempted to make unified theory, not successful Name ________________________________ Go to: http://www.classzone.com/books/earth_science/terc/navigation/investigation.cfm Scroll down to Chapter 26 and click on: ‘How Does the Sunspot Cycle Affect Earth?’ Step 1: Spots on the Sun 1. Why do sunspots move across the face of the sun? 2. What do the sunspot regions look like in the x-ray images? How might the activity at these areas affect Earth? Step 2: Solar Wind 1. How fast does the solar wind stream out into space? ________________________ 2. What protects us from these solar particles? _________________ 3. Earth is 150 million kilometers from the sun, and the solar "wind" travels at about 400 km/sec. How long does it take particles from a solar storm to reach Earth? (Hint: Time = Distance / Speed. To convert from seconds to hours, divide the time in seconds by 3600.) 4. What do you think would happen if Earth's magnetic field became weaker or disappeared entirely? Step 3: Short-Term Effects 1. What are the effects on each feature below? -Space Shuttle/Astronauts: -Satellites: -Air Travel -Communications Systems -Power Lines -Animals -Navigation -Pipelines Step 4: Solar Cycles 1. How are the two graphs on this step different? 2. What is the average time interval between solar maxima? Step 5: Long Term Effects 1. Why can’t sunspot data be compared to environmental data accurately? 2. What environmental measure best correlates to sunspot activity? Step 6: Space Weather 1. Identify three jobs held by people who would need to check the space weather report regularly, and explain why the report is important to each. Name ________________________ What Does the Spectrum of a Star Tell Us about Its Temperature http://www.classzone.com/books/earth_science/terc/navigation/investigation.cfm Go to: Chapter 28- Stars and Galaxies and click on above title. A. Looking at Starlight 1. What spreads light into a spectrum? ________________________ 2. Please draw the diagram where starlight from a telescope is spread into its component colors to form a spectrum. B. Examining Spectral Patterns 1. Record a list of the spectra in 3-4 groups. Describe the criteria below each group you used to categorize the spectra. Group 1 ____________________________________Group 3 ________________________________ Group 2 ____________________________________Group 4 ________________________________ C. Standard Spectra 1. Record a list of the spectra you assigned to each group. How does this classification scheme compare with your first one? A __________________ C ____________________ B __________________ D ____________________ __________________________________________________________________________________ __________________________________________________________________________________ D. Line Spectra and Peak Emission Wavelength 1. Record the peak emission wavelength for each of the four standard stars. A __________________________ B ____________________________ C __________________________ D ____________________________ E. Peak Emission Wavelength and Temperature 1. Record the temperature indicated by peak emission wavelength for each of the four standard stars. ABCD- Peak Wavelength ___________ Peak Temperature ___________ Peak Wavelength ___________ Peak Temperature ___________ Peak Wavelength ___________ Peak Temperature ___________ Peak Wavelength ___________ Peak Temperature ___________ F. Peak Emissions for Spectral Groups 1. Record the peak emission wavelength for each star's spectrum. (Make sure to list the star #) A.: ___________ B: ___________ C. ___________ D. ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ 2. Based on the peak emission wavelengths and the temperatures of the standard stars, estimate the temperatures of stars in each category. A: ___________ B. ___________ C. ___________ D. ___________ G. Estimating Temperature of Unknowns 1. Match the spectra on the left with the appropriate column and estimate the temperature of the stars from the left side. A. _______ Temperature: __________ B. _______ Temperature: __________ C. _______ Temperature: __________ D. _______ Temperature: __________ H. Real Spectral Classes 1. What is the surface temperature of an O star? __________________________ 2. What is the spectral pattern for an O star (where does it emit light?) ______________________ 3. What is the surface temperature of a K star? __________________________ 4. What is the spectral pattern for a K star (where does it emit light?) ______________________ 5. How many times hotter is an O star than a M star(show work below)? ___________________