Turn off the daylight display. Using the “Selection” button,
select “Find”. Type in the name “Ursa Major” and
click on Find. Go to “Guides” then Constellations and select
Astronomical. This should show you the boundaries
of Ursa Major and the outline of the constellation. Using
the Selection Tool, click on one of the stars in Ursa Major.
Open the “Display” Palette on the vertical toolbar and
click on the Const button. One by one, use the Selection
Tool to point at the stars that outline Ursa Major (there
are 20 of them), and right click with the mouse. Then
click on Info Window. Record the name of the star, its
temperature, and B-V Colour Index. (For Alkaid, the star
at the end of the handle of Ursa Major, the temperature
and B-V Colour Index are 11,235 and 0.10.) B-V
Colour Index is the difference between the magnitudes of
the star in the middle of the visual part of the spectrum
and the blue part of the spectrum. Arrange the stars according
to temperature from hottest to coolest. How is
B-V related to temperature? Explain the relationship between
B-V and stellar temperature.
