Review Astronomy 1 — Elementary Astronomy LA Mission College Spring F2015 Quotes & Cartoon of the Day “One may wonder, What came before? If space-time did not exist then, how could everything appear from nothing? . Explaining this initial singularity—where and when it all began—still remains the most intractable problem of modern cosmology. — Andrei Linde “But who shall dwell in these worlds if they be inhabited? ... Are we or they Lords of the World? ... And how are all things made for man?” — Johannes Kepler “Our sun is one of 100 billion stars in our galaxy. Our galaxy is one of billions of galaxies populating the universe. It would be the height of presumption to think that we are the only living things in that enormous immensity.” — Wernher von Braun Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Announcements • Observing Project & Extra Credit Due • Midterm graded & gradebook updated to drop lowest • remainder of grading (hopefully) updated this weekend • Final 12/15 at 10-12 AM! Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Last Class • Debrief Midterm • Debrief LT • Cosmology & Fate of the Universe • Exoplanets (time permitting) Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 This Class • Review/Debrief Midterm • Exoplanets (time permitting) Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 About the Final Astronomy 1 — Elementary Astronomy LA Mission College Spring F2015 About the Final • Similar format to Midterms • Similar length • a little longer, some choice of questions • Little new material, mostly cumulative • Study the stuff on the midterms! • But don’t memorize the questions themselves, you probably won’t see many that are identical • You may bring a full sheet of notes • both sides • handwritten Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 About the Final • Don’t leave stuff blank! • Can you remember ANYTHING about the topic? • Apply logic! • Comprehension before Computation -- Big Picture before Details • State units with numbers (except magnitude) Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Topics Astronomy 1 — Elementary Astronomy LA Mission College Spring F2015 TOUR OF UNIVERSE Our “Cosmic Address” • LAMC • Sylmar • Los Angeles County • CA • US • Earth • Solar System • Milky Way Galaxy • Local Group • Virgo Supercluster • The Universe Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 SCIENCE Science • Definition • Method • KEY: Hypothesis, Test, Revision • Nomenclature -- Hypothesis, Theory • Characteristics of Science & Belief System • Be able to recognize science and not-science • Be able to recognize a scientific hypothesis • Be able to describe the scientific method Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 THE NIGHT SKY Diurnal Motion • Daily • Everything Rises in East, sets in West • Moves in circles around the NCP (and SCP) • Earth is rotating • Be able to answer questions using diagrams from the Position LT Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Lunar Phases • Cause of phases • ID of phases • Timing of rise/set/transit Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Eclipses • Solar and Lunar • Cause • Geometry • Timing • Why not every full/new moon Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Zodiac & Apparent Solar Motion Name:____________________!! Date:__________ ICE 2! ASTRO 110/120! Levine Spring 2013 • Ecliptic • Zodiac • Meaning of “The Sun is in Taurus etc.” • Takes a year to cycle through Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Seasons • It’s the axial tilt • It’s about energy transfer • Be able to discuss observable consequences • when is the Sun high in the sky, day length etc. Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 OLD DEAD GUYS Greeks to Kepler • Greek ideas • Copernican Revolution • Tycho Brahe • Kepler the dude Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Kepler’s 3 laws of Planetary Motion 1. The orbits of the planets are ellipses, with the Sun at one focus. 2. A line from a planet to the Sun sweeps out equal areas in equal periods of time • Planets move fastest when physically closest to the Sun, and slowest when farthest. 3. A planet’s orbital period squared, is proportional to it’s farthest distance from the Sun cubed: • P2 = a3 • Be able to recognize these • Work with ellipses and eccentricity • Recognize examples of 2nd and 3rd law (faster/slower longer period/ shorter period) • Possible calculation with 3rd law Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Kepler to Sir Issac • Galileo • Sir Issac • Contributions and fields of study • Law of Universal Gravity Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Law of Universal Gravity • Be able to explain how the force varies (larger or smaller) with mass of either object, both objects and distance • Be able to work the inverse square relationship -- how does force change if distance doubles.... Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 LIGHT, OPTICS, TELESCOPES Nature of Light • Why this is important for Astronomy • electromagnetic radiation • waves, particles, duality • all light, from radio to gamma ray is same thing • all light travels at the same speed in vacuum • c=3x108 m/s Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Properties of Light • Waves • Relationship of wavelength and frequency • λ = c/f • Interference • Particles • Photoelectric effect • E = h f = hc/λ • h = 6.6 x 10-34 Js = 6.6 x 10-34 J/Hz • Know what these relationships mean • Know how the ranking task worked • Possibility of seeing a a simple calculation Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Electromagnetic Spectrum • difference between red and blue light • Basic bands of EMR (e.g. radio, visible, IR etc.) • Relationship between band, wavelength & Energy Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Telescopes and Observatories • Refractors and Reflectors • Size (of primary) matters • Atmospheric Transmission & Seeing • Multiwavelength Astronomy • What are IR and Radio good for? • Cameras & Spectroscopes Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 SOLAR SYSTEM Solar System Properties • Overall “bulk” properties • Disk shape • two types of planets • Space “debris” • common age Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Solar System Properties • “Anatomy” What and Where • Sun • Inner SS & terrestrial planets • Asteroid Belt • Outer SS & Jovian planets • Kuiper Belt • Heliopause • Oort cloud • Size/Distance Scales Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Solar System Formation • Raw materials -- big bang, role of supernovae • Theories of Formation • Solar Nebula Theory • Differentiation • Frost line • Planet formation -- both types • Disk clearing • Cratering & Craters Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Solar System Bodies • Terrestrial Planets • common properties • dynamo effect • What went wrong for Venus and Mars • Greenhouse effect • Jovian Planets • common properties • Why are Titan and Enceladus interesting • Why isn’t Pluto a “planet” and what it is Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 STARS & GALAXIES Stellar Properties • Luminosity • Magnitude system • Apparent vs. Absolute magnitude • review the ranking tasks • Distance ladder & difficulty of distances • Stellar parallax • know how angle & distance relate • Standard Candle • how does a standard candle work Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Color and Temperature & Size • stars are (mostly) like blackbodies • temperature and peak wavelength • temperature and size & luminosity Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Spectral Type • Color ~ temperature ~ spectral class • be able to answer questions based on the blackbody LT • Harvard computers & Harvard classification scheme • OBAFGKM • Brightness and temperature and size (Giants) Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 HR Diagram • What is it? • What can be plotted on it? • Main sequence • Red giants • Supergiants • White Dwarfs • Evolution Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Stellar Lifecycles © NASA • Star formation • Main Sequence lifetime • End states and what determines them • Mass is everything!!!!! • More mass means shorter life Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Main Sequence & Red Giant phase • Main Sequence • Hydrostatic Equilibrium • H to He nuclear fusion • Most of a star’s life • Sun is on MS • Red Giant • New hydrostatic equilibrium • H to He fusion in shell • He fusion in core • 1/10th the duration of MS lifetime Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Endgame Scenarios • Giant stars • Planetary nebulae • White dwarfs • Type II supernovae • neutron stars & pulsars • black holes • type Ia supernovae Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 The Milky Way • Barred Spiral • General structure • disk, bulge, halo • General Content • Where are we? Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Galaxy Classification NASA/ESA Astronomy 1 - Elementary Astronomy LA Mission College Levine F2015 Characteristics of types • Describe spirals, barred spirals,