Using Star Charts and Maps
 

Activity:
Students investigate the information provided on star charts.

Science Standards
Nature of Science and Scientific Models (Scale & Conceptual)

Objectives:

  • The student will describe the location of objects found on star charts.
  • The student will use Right Ascension and Declination Coordinates.
  • The student will identify the following characteristics on star charts:
    1. brightness of stars
    2. variable stars
    3. multiple-star systems
    4. nebulae
    5. galaxies
    6. Messier Objects
    7. Bayer Star Designations
    Materials:
    Copies of star charts that include equatorial coordinates and celestial objects.


    Introduction:
    RA/Dec.  Astronomers locate the position of celestial objects using a equatorial coordinate system that is similar to the latitude/longitude system used on Earth. How far an object is above or below the celestial equator is measured in degrees of Declination. How far east an object is from the vernal equinox is measured in hours, minutes, and seconds of Right Ascension. This information is usually provided on star charts.
    Alt/Az.  Another way to measure the location of an object from a particular location is by the altitude above the horizon and by the direction. The direction is measured in degrees clockwise from the north; this number is called azimuth. This information is rarely provided on any star charts.
    Messier Objects.  Comet hunter Charles Messier found that there were a number of permanently "fuzzy" objects in the sky that repeatedly interfered with his research. He developed a catalog of 105 objects that are known as Messier Objects. They are labeled as M1, M2, M3, etc.
    Bayer Designation.  The brightest stars of a constellation are labeled using Greek letters as a, b, g, d and so on. The brightest star is usually a, the next brightest b, to dimmer and dimmer stars.
     

    Directions:
    1. Identify how many "things" that can be found on a star chart using the legend.
    2. Find and list and example of each item shown in the legend.
    3. Determine the coordinates of the five brightest stars on a chart.
    4. Write the directions to find a "mystery object" and ask other students to locate and identify the object.