Time: Approximately 30-45 minutes
Materials: Whiteboard or prepared transparencies for explanation of stellar parallax, student computers connected to the Internet, student instructions and worksheets, rulers
Prerequisites: Before starting this activity, students should understand the distance measurements commonly used in astronomy (astronomical unit, light year, parsec). (The definition of parsec can be introduced during your introductory remarks on the parallax method.)
Implementation: This RWLO can be used in a classroom or lab equipped with computers. With prior presentation of the concept of stellar parallax, it can also be given as an individual or group assignment.
Explain the parallax method of determining distances to nearby stars. (If this is given as an assignment outside of class, a useful resource for this step can be found on the internet at .)
Distribute the student instructions and worksheets.
Assign the named stars in Orion (see worksheet) to individual students, if desired. Otherwise, have individuals or groups do the entire list of 7 stars.
Students access SIMBAD and get parallax data (Worksheet 1).
Students calculate the distances in parsecs and light years (Worksheet 1).
Students then prepare a chart, using Worksheet 2, showing the relative distances to the stars.
Students draw a conclusion about the distances to named stars in the constellation.