1 / 30

Unlocking the Cosmos: Exploring Telescopes and Their Functions

Discover the world of optical telescopes, from reflectors to refractors, understanding concepts like light-gathering power, magnifying power, and resolving power. Learn about telescope designs such as the Newtonian and Cassegrain reflectors, and delve into the fascinating realm of radio interferometry and X-ray telescope technology.

fant
Download Presentation

Unlocking the Cosmos: Exploring Telescopes and Their Functions

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.

E N D

Presentation Transcript

  1. Chapter 4: Telescopes

  2. Optical telescopes: Reflectors and refractors E O Refractors use lenses E: eyepiece O: objective

  3. Reflectors use mirrors: Newtonian Cassegrain

  4. Objective (O) = Main light-gathering surface (lens or mirror) Aperture= a = Diameter of objective ("size" of telescope) Focal length= f = Distance from objective to image ("length" of telescope) Eyepiece (E) = Lens used to inspect image from objective

  5. 1) LIGHT GATHERING POWER (how faint you can see) • LGP ~ a2 (Bigger = better) • 2) MAGNIFYING POWER (how large image is) • MP = f(O) / f(E) (Bigger = better) • So can change this with eyepice choice, not a fundamental property of telescope • Practical limit  50 x O (in inches) • 3) RESOLVING POWER (size of detail, sharpness of focus) • Size of detail ~ 1/a (Smaller = better) • i.e., larger ‘a’ allows smaller details to be seen

  6. Resolution vs. magnification

  7. Airy disk. Light coming through a circular aperture

  8. Resolution vs. magnification

  9. Atmospheric seeing

  10. The planet Uranus imaged in the infrared

  11. Spitzer Space Telescope An infrared telescope in orbit around the Sun!

  12. 43 m diameter

  13. How to improve resolution? Radio interferometry The Very Large Array, Socorro, New Mexico

  14. VLBI

  15. Chandra Xray observatory

  16. X-ray telescope design (Chandra X-ray Observatory) It is very difficult to focus (redirect) high energy photons, because they are so readily absorbed by matter. Thus it is difficult to tell where they came from, and to reconstruct the image.

  17. Chandra image of X-rays emitted from hot gas surrounding galaxy Cygnus-A

  18. An Xray image of a black hole, by Chandra.

  19. X-ray image Visible (optical) Hot stars give off a lot more Xrays than cooler stars do.

  20. Observing gamma rays Space-based telescopes (Compton Gamma ray Observatory

More Related