Human beings have looked up to the night sky since before recorded history. Because we are fanciful types, we have named the stars and told stories about the sky. More recently, we have applied science to the stars. What things can be measured about the stars? That was the main task of nineteenth century astronomers. By using large telescopes that took images on glass photographic plates, astronomers where able to methodically measure things such as brightness, which was related to the size of the star image, With many exposures taken over a period of many years, the motions of stars could be measured. This was a very tedious process, which led to the first understanding of our neighborhood in the Milky Way Galaxy. Here are the main observational characteristics of stars that can be measured or defined: • Apparent and absolute magnitude of stars • Distances to the stars (in light years or parsecs) • Stellar Parallax • Radial Velocity • Proper motion

Check out my Stellar Properties Powerpoint