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Astronomy Seeing through different light…. VisibleUV..

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Presentation on theme: "Astronomy Seeing through different light…. VisibleUV.."— Presentation transcript:

1 Astronomy Seeing through different light…

2 VisibleUV..

3 VisibleIR

4 VisibleRadioXray

5 Venus -IR

6 Venus -UV

7 Venus -RADIO

8 Venus -VISIBLE

9 Types of Light Gamma rays X-Rays UV rays Visible Rays Infrared Microwaves Radio Long Waves

10 Types of Light Gamma rays –Nuclear blast X-Rays –Go through skin and body, stopped by bone UV rays –Penetrates skin, causes damage

11 Types of Light Visible Rays –What we can see Infrared –Night vision goggles Microwaves –Excite water Radio Long Waves

12 Optical Telescopes Why do astronomers use telescopes? –Magnification –Resolution –Brightness

13 Brightness Gathering light to make faint objects appear bright MOST important Depends on the size of the lens

14 Resolution How sharp an object looks Larger the lens, higher the resolution HDTV vs. normal tv



17 Magnification How many times larger an object looks LEAST IMPORTANT

18 Magnification calculations M = fo/fe Fo = Focal length of the objective Fe = Focal length of the eyepiece

19 How big is our universe? MONTE PYTHON VIDEO

20 Optical Telescopes Relflectors and Refractors

21 Refractors Uses lenses to bend light

22 Refractor

23 Objective lens Eyepiece

24 Focal Length The distance from a lens to the focal point Focal Point The point where light rays converge to produce an in focus image

25 Two lenses are placed at their focal lengths apart Fo (focal length of objective) + Fe (focal length of eyepiece) = Length of telescope

26 Fo = 1000mm Fe= 20 mm What is the length of the telescope? What is the magnification?

27 Activity Right Eye Focal Length: Left Focal length: Both eyes

28 II. Focal Length of a lens Focal Length of Lens 1: Focal Length of Lens 2:

29 III. Magnification Draw a small arrow Measure it in cm

30 Reflector Telescopes Newtonian and Cassegrain

31 Newtonian Reflector Uses a mirror to reflect light

32 Newtonian Reflector

33 Cassegrain Reflector Has eyepiece behind mirror Has a small hole drilled into the middle of the objective mirror so that they light can go through

34 Cassegrain

35 Refractors PROS Better resolution due to no diagonal mirror blocking part of the objective CONS Chromatic Abberation (colors smear) Size limit on objective lens - if glass lens is too big it will sag) - max size = 3 feet

36 Reflectorss PROS No size limit –The objective mirror can be made up hundreds of smaller mirrors Easier to hook up a computer to CONS Slightly less resolution

37 Optical observatories Keck 1 and Keck II in Hawaii


39 Hubble Space Telescope


41 GEMINI in Chili


43 Places to Build optical observatories Away from cities Away from light pollution Mountain tops or space The more atmosphere a telescope looks through, the blurrier the image

44 Atmospheric Window Transparent to: Visible and Radio Semi-Transparent to: Infrared Opaque to: UV, X-Ray, Gamma Ray

45 Radio Telescopes Parts –Dish: :Large dish that focuses the rays (does not have the be smooth) –Receiver: Gathers the rays and send to a computer to analyze


47 FALSE COLOR IMAGE: –Bright Areas= high intensity –Dark Areas= low intensity RESOLUTION: - Since radio waves are very large, they have very low resolution

48 Interferometer Array A way to increase resolution Observe the same object with lots of different telescopes Send all data to computer to create a high resolution image


50 Length of telescope Distance the telescopes are separated

51 Where to place Radio Telescopes Valleys –Avoids radio interference (mountains block the signal)

52 Examples of Radio Observatories Arecibo –Worlds largest single radio telescope –Puerto Rico

53 VLA –Very large array –New Mexico –On Train Tracks

54 VLBA –Very large Baseline Arrary –Array of the worlds largest telescopes –Size of earth

55 Infrared Telescopes Uses regular mirrors Must be placed high in the atmosphere

56 Sophia Aircraft with a telescope built in it

57 Spitzer In space Studies stars and planet formation

58 Telescope Videos e_deep_field/

59 Argons spectra The colored lines on the spectrum come from Argons electrons relaxing back to the ground state and releasing photons Fingerprint/Bar code Each element/compound has unique spectra

60 Hydrogen Less lines = less energy levels/electrons

61 Helium

62 Where should we put telescopes?

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