1 / 61


Instruments. Why use a telescope?. Light gathering : telescopes collect more light than the human eye can capture on its own Magnification. Refractor Telescopes. http://www.bro.lsu.edu/telescope/Classroom/2.How%20Telescopes%20Work/Refracting.gif.

Télécharger la présentation


An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.


Presentation Transcript

  1. Instruments

  2. Why use a telescope? • Light gathering: telescopes collect more light than the human eye can capture on its own • Magnification

  3. Refractor Telescopes http://www.bro.lsu.edu/telescope/Classroom/2.How%20Telescopes%20Work/Refracting.gif

  4. Refraction - the bending of light due to the fact it slows down while going through a dense medium.

  5. Refractors • Size refers to the size of the objective lens • The bigger the objective lens, the more light gathering power the telescope has

  6. Yerks Observatory, U Chicago Williams Bay, WI http://astro.uchicago.edu/yerkes/

  7. Yerkes Observatory • Largest refractor • 40 inch objective (102 cm) http://astro.uchicago.edu/vtour/40inch/40inchtour.jpg

  8. Magnification The focal length of the objective lens Magnification = ------------------------------------------------ The focal length of the eyepiece How can you change the magnification without changing the light collecting power?

  9. Warm up: • Which part of a refractor telescope is light gathering? • What does the magnification?

  10. Amazing History of the Telescope • ESA: Eyes on the Skies Chapter 1 • http://www.youtube.com/watch?v=A68Hta5RxWg

  11. Refractor- Advantages • After initial alignment, refractor optics are more resistant to misalignment • The glass surfaces are sealed inside the tube and rarely need cleaning. • The sealing also minimizes affects from air currents, providing steadier sharper images. http://space.about.com/cs/telescopes/a/scopebasics.htm

  12. Disadvantages • possible distortions of the lenses. • lenses need edge supported, this limits the size of any refractor • Lenses can “sag” over time • Chromatic aberration

  13. Chromatic Aberration • only 1 frequency focuses at a time because of dispersion • each frequency slows a different amount in glass http://www.astronomynotes.com/telescop/s2.htm

  14. Chromatic Aberration http://www.astronomynotes.com/telescop/s2.htm

  15. Reflector http://d1jqu7g1y74ds1.cloudfront.net/wp-content/uploads/2008/07/reflecting.gif

  16. http://telescopeguide.net/wp-content/uploads/2013/01/REFLECTOR-diagram.jpghttp://telescopeguide.net/wp-content/uploads/2013/01/REFLECTOR-diagram.jpg

  17. http://web.williams.edu/astronomy/Course-Pages/111/Images/reflect-tel-types.gifhttp://web.williams.edu/astronomy/Course-Pages/111/Images/reflect-tel-types.gif

  18. Mt. Wilson Hooker reflector • 100 inch mirror (2.5 m) • Biggest telescope between 1917 - 1948 http://www.mtwilson.edu/vir/100/

  19. Palomar Observatory (Cal Tec) http://www.astro.caltech.edu/palomar/images/speed.limit.jpg

  20. Palomar Observatory • California Institute of Technology • North of San Diego, CA • 5 telescopes

  21. Hale telescope http://www.astro.caltech.edu/palomar/

  22. Reflectors- advantages • Reflectors do not suffer from chromatic aberration (inability to focus all colors). http://space.about.com/cs/telescopes/a/scopebasics.htm

  23. Advantages (cont’d) • Mirrors are easier to build without defects than lenses, since only one side of a mirror is used. • because the support for a mirror is from the back, very large mirrors can be built, making larger scopes.

  24. Reflectors- Disadvantages • The disadvantages include easiness of misalignment and need for frequent cleaning. http://space.about.com/cs/telescopes/a/scopebasics.htm

  25. For a telescope, why is bigger better?

  26. Advances in Ground Based Telescopes

  27. Ground Based Telescopes of Note

  28. Keck I & Keck II • 300 tons each http://amazing-space.stsci.edu/resources/explorations/groundup/lesson/scopes/keck/graphics/map_keck.jpg http://www.ucolick.org/~kibrick/remoteobs/jtechs2001/distantkecks_5B1_5D.jpg

  29. This is the rear of the primary mirror assembly http://upload.wikimedia.org/wikipedia/commons/c/c0/Rear_of_Primary_Mirror_of_Keck_Telescope.jpg

  30. Keck Telescope 10 m

  31. http://www4.uwsp.edu/physastr/kmenning/images/keck-diagram.jpghttp://www4.uwsp.edu/physastr/kmenning/images/keck-diagram.jpg

  32. Interferometry • Using multiple small telescopes to form an image effectively simulating a much larger telescope • http://planetquest.jpl.nasa.gov/technology/technology_index.cfm

  33. Problems with Ground Telescopes • "atmospheric distortion" is the reason that the stars seem to twinkle when you look up at the sky • atmosphere partially blocks or absorbs certain wavelengths of radiation, like ultraviolet, gamma- and X-rays, before they can reach Earth

  34. Looking beyond the visible

  35. Published 02 April 2009The University of Waikato

  36. Infrared Energy • heat energy • Observed in dry, high altitude locations or space • Observation of: • galactic regions cloaked by dust • studies of molecular gases. NASA Infrared Telescope Facility- Mauna Kea, Hawaii

  37. Spitzer http://www.spitzer.caltech.edu/mission/where_is_spitzer

  38. Ultraviolet View of the Astro-1 astronomical observation payload in the bay of Shuttle Columbia during the STS-35 mission of December 1990 • absorbed by atmospheric ozone • observed from very high altitude or space • best suited to the study of thermal radiation and spectral emission lines from hot blue stars that are very bright in this wave band

  39. X-Rays Electromagnetic Energy Chandra X-ray Telescope • absorbed by atmosphere • Observed by high altitude balloons, rockets, or from space Notable X-ray sources include: • X-ray binaries • pulsars • supernova remnants • active galactic nuclei

  40. Fermi X Ray Telescope Fermi Bubbles - found by the Fermi telescope in 2010 - extend 20,000 light-years above and below our Milky Way galaxy.

  41. Fermi X Ray Telescope • http://earthsky.org/space/mysterious-objects-at-edge-of-electromagnetic-spectrum Fermi Bubbles - found by the Fermi telescope in 2010 - extend 20,000 light-years above and below our Milky Way galaxy.

  42. Gamma ray Electromagnetic Energy • observed in space or indirectly with special ground based telescopes Steady gamma-ray emitters include: • Pulsars • neutron stars • black hole candidates such as active galactic nuclei Compton Gamma-ray Observatory launched on the Space Shuttle Atlantis, mission STS-37, on 5 April 1991 and operated until its de-orbit on 4 June 2000

  43. Why do astronomers use a variety of telescopes?

  44. Hubble

  45. Nat Geo- Hubble • Read Hubble Space Telescope-Eyes in the Sky • Complete the article/text analysis document

  46. DATA PATH BEFORE IMAGE IS CREATED HOW IMAGES ARE MADE!! http://hubblesite.org/gallery/behind_the_pictures/

  47. The new image (right) was taken with the second generation Wide Field and Planetary Camera (WFPC2), which was installed during the STS-61 Hubble Servicing Mission. The picture beautifully demonstrates that the corrective optics incorporated within WFPC2 compensate fully for Hubble's near-sightedness. The new camera will allow Hubble to probe the universe with unprecedented clarity and sensitivity. The picture clearly shows faint structure as small as 30 light-years across in a galaxy tens of millions of light-years away. An Early Release Observation Release / An American Astronomical Society Meeting Release January 13, 1994

  48. Hubble Telescope • 353 miles (569 km) above the surface of Earth • Every 97 minutes, Hubble completes a spin around Earth • moving at the speed of about five miles per second (8 km per second) — fast enough to travel across the United States in about 10 minutes

  49. Hubble

More Related