9. How Far the Stars?

Joshua Barnes -- Fall 1999

Topics:

• Distance scales
• Parallax
• Luminosity & brightness
• Standard candles
• HR diagrams

Web Resources:

• Hipparcos Results

  The Hipparcos satellite measured positions and parallaxes for thousands of stars with enormous accuracy.

• The Star Mapper

  A superb essay by Philip Morrison describing early measurements of stellar parallax and contrasting them with Hipparcos. Highly recommended!

• The Solar Neighborhood (3 Mbyte gif animation)

  Animation of the 150 nearest stars, made using Hipparcos data. Color indicates stellar luminosity: blue stars are above 10 L, yellow stars are between 1 and 10 L, orange stars are between 0.1 and 1 L, and red stars are below 0.1 L.

Homework 9: Finding Distance With Parallax, due 10/25.

Quiz 9: Is The Sun A Star?