2. Electromagnetic Spectrum  EM Spectrum – a continuous range of wavelengths  Longer wavelengths = low energy  Ex. – radio waves, microwaves  Shorter wavelengths = high energy  Ex. – X-Rays, Gamma rays (mutations! Ah!)  We see a very small portion – visible light

3. Electromagnetic Spectrum

4. Intrumentation  Telescopes  Collect more visible light than the naked eye  Help see objects further away in space  Ex. - Hubble Telescope  Spectroscopes  Spread light into different wavelengths  Used to study stars’ characteristics  Can examine wavelengths our eyes can’t see

5. Distance in Space (it’s big)  Parallax  Looking at an object from two different points and using that to determine position  Astronomical Units  A unit used within the solar system  The distance from the Earth to the sun  Light-Years  A MEASURE OF DISTANCE!!!! (know this! VIMP!)  Amount of distance light travels in one year Light traveling

6. Distance in Space

7. Brightness of Stars (so pretty….)  Absolute magnitude – the true brightness, doesn’t matter where you are looking from  Luminosity depends on temperature, spectra, and the size of the star  Distance from Earth does NOT matter  Apparent magnitude – how bright the star looks in the sky (can use your own eyes)  The scale is strange….brighter stars can have a negative number and fainter stars can have a positive number (thanks, Hipparchus)

8. Brightness of Stars Apparent Magnitude