1. The Electromagnetic Spectrum and Telescopes Rose Emanuel Journey into Space Journey Museum, July 18-20, 2012

4. Major Space Observatories Why put them in space?

5. Atmospheric Blurring – Twinkling of stars in sky, called scintillation, is caused by moving atmospheric irregularities refracting star light into a blend of paths to the eye – Distorted seeing can be improved by adaptive optics, which employs a powerful laser and correcting mirrors to offset scintillation

6. Light Pollution

7. Space vs.Ground-Based Observatories Space-Based Advantages – Freedom from atmospheric blurring – Freedom of atmospheric absorption Ground-Based Advantages – Larger collecting power – Equipment easily fixed Ground-Based Considerations – Weather, humidity, and haze – Light pollution

9. The Hubble Space Telescope (HST) is able to observe in the ultraviolet, something that ground-based research telescopes cannot do.

10. X-ray Telescope: Chandra High energy x-rays must skip off the shiny mirror surface at shallow angles to be observed, much different than how optical light telescopes work. Collecting x-rays is like skipping stones on a pond!

11. Gamma Ray Detectors Gamma rays have too high an energy to be focused with even the shallow angle reflecting technique, so gamma ray telescopes simply point in a desired direction and count the number of photons coming from that direction. The Compton Gamma Ray Observatory

12. “Invisible” Light in Astronomy Each part of the spectrum provides a piece of the puzzle in understanding our universe. Star birth & star death Warm dust Stars & dust Young stars Black holes & neutron stars

13. Ultraviolet Images of a Galaxy Clearly Show the Young, Hot Stars

14. Infrared measurements in Andromeda clearly reveal the hot dust

15. The Crab Nebula: The Aftermath of a Supernova The Crab Nebula is all that remains of a once-bright star. The white box on the left shows the area covered by the image on the right.

16. A visible light image of Centaurus A, an interesting galaxy observed with a wide lane of dust across its center. Visible Light View of an Interesting Galaxy, but X-rays Reveal the Real Action! A high-energy jet blasts outward from the galaxy’s center, evidence for a powerful black hole with the mass of one billion Suns!

17. The infrared reveals the clouds of gas and dust associated with starbirth

18. X-ray observations of the center of our own galaxy clearly reveal the hot gas swirling into a massive black hole