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Project AstroFly Examples: Our Sun in the Hertzsprung-Russell Diagram


This image, generated by AstroFly, shows our Sun's position in the Hertzsprung-Russell diagram, marked by a violet cross. Any star you see in AstroFly may be displayed in the Hertzsprung-Russell diagram the same way. The H-R diagram itself displays an interesting correlation between temperature (B-V color index) and luminosity (absolute magnitude). The Sun lies in the middle of the diagonal band in the diagram. The band is called the main sequence where stars spend most of their life time, moving on it from the upper left to the lower right. The red giant and supergiant stars are in the upper right of the diagram.

If you use the star database derived from the Tycho Catalogue, you may see that our neighborhood in our own Milky Way Galaxy is full of old stars that have exhausted their nuclear fuel; the white dwarfs are visible in the lower left of the diagram; the red dwarfs, in the lower right.


To get this view in AstroFly, follow these steps:
  1. Start AstroFly.
  2. In the Main Control Panel, uncheck the box Limit Visual Magnitude (from the Sun).
  3. Choose Tools > Find Star.
  4. In the Find Star By dialog box, enter the text SUN into the Name field, and click the Find It button.
  5. In the Information about This Marked Star window, click the Show It in H-R Diagram button.