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3.0 – Telescopes and Interpreting space. 3.1 Telescopes -. Optical Telescopes – gather and focus light of stars to create a visible image of stars - the larger the area of the lens, the more clear the light 1. Refracting telescope- uses 2 lenses to enlarge images (images are upside down).
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3.1 Telescopes - • Optical Telescopes – gather and focus light of stars to create a visible image of stars - the larger the area of the lens, the more clear the light 1. Refracting telescope- uses 2 lenses to enlarge images (images are upside down) Lens #2 Eyepiece lens #2
3.1 . Telescopes 2 . Reflecting Telescopes – Uses a mirror to gather and focus light -can pick up more faint light than reflecting Video clip: Telescopes
Summary of Telescopes Refracting Reflecting • Uses two lenses to focus and gather light • Used best for looking at objects within our galaxy Planets, moons, etc. • Uses a lens and mirrors to gather/focus light • Best used for viewing far away objects – is better at gathering and focusing light
3.1 - Telescopes B. Interferometry– using 2 or more telescopes in combination to improve the resolution (clarity and details) of images Array used on the Andes Mountains in Chile VLT (Very Large Telescope) Is a collaborative effort between NA, Europe and East Asia
The Keck Interferometer links two 10-meter (33-foot) telescopes on Mauna Kea in Hawaii. The linked telescopes form the world's most powerful optical telescope system. They will be used to search for planets around nearby stars, as part of NASA's quest to find habitable, Earth-like planets
***Array – the arrangement of telescopes used for interferometry Military array of telescopes in Arizona
3.1 Telescopes C. Hubble Space Telescope • A reflecting telescope 600km above Earth’s surface • Allows star-gazing without interruption of clouds • Rotates Earth every 95 mins. Which orbit would the Hubble Space telescope be placed in?
Picture from Hubble Space Telescope of nearby spiral galaxy Messier 74. [2007]
Picture from Hubble Telescope of Crab Nebulae. The Crab Nebulae is the reminants of a supernove and in the center lies a neutron star. [6500 light years from Earth]
3.2 Seeing Beyond Invisible A. Electromagnetic Energy - a form of energy that travels in waves through space • Includes: infared, visible light, ultraviolet light • Wavelength – length of the wave • Frequency – the amount of waves that pass through a point in a second • High frequency energy has low wavelength • Low frequency energy has high wavelengths
3.2 Seeing Beyond Invisible B. Radio Telescopes • Pick up radio waves and create maps of the galaxy • Radio waves are emitted by planets, the Sun, stars, etc. • Advantage over Light Waves: These waves are unaffected by weather or the atmosphere • Video Clip: Milky way emits radio waves
3.2 Seeing Beyond Invisible C. Ways to Improve Radio Telescope Maps • Interferometry – combine two or more radio telescopes (will be better than 1 large one) • Increase distance between telescopes (can better plot positions) • Arrange telescopes into arrays – (Y shapes)
3.3 Interpreting Space • Measuring Distance 1. Triangulation • Using a triangle to determine the distance to an object • A baseline is measured and the two angles from the baseline ends to the object • A drawing to scale is completed and measured. • The longer the baseline the more accurate the measurement
3.3 Interpreting Space 1cm = 1m
3.2 – Interpreting Space 2. Parallax – is the apparent shift of an object when it is viewed from two different places -used to determine angles for triangulation Try IT: Parallax of Your Finger! -close one eye at a time
3.2 – Interpreting Space B. Determining A Star’s Composition • A spectroscope is used to determine what elements a star is made of • Each element makes a distinct thickness and location in a visible light spectrum
Why does the sound change??? http://www.colorado.edu/physics/2000/applets/doppler2.html -
C. Determining A Star’s Movement • Doppler effect- when the movement of an object makes waves compress or spread out • Makes an object coming closer sound higher in pitch and lower moving away • Stars moving towards Earth show a spectrum that is blue shifted • Stars moving away from Earth show a red shift spectrum