The spreadsheet carries a list of stars together with their apparent magnitudes, distances, and temperatures. For each one calculate the absolute magnitude and enter it in the blank column labeled M. Use the formula:

where d is the distance in parsecs to have Excel calculate M for you.

2. Use interpolation from the following table to estimate the spectral type of each star. Enter type in column Spectral Type. (If you don't know what interpolation means, look it up!)

Spectral Type Temperature (K)

O5
40,000

B0
28,000

B5
15,500

A0
9,900

A5
8,500

F0
7,400

F5
6,580

G0
6,030

G5
5,520

K0
4,900

K5
4,130

M0
3,480

M5
2,800

M8
2,400

3. Use Excel to make an H-R Diagram. Or feel free to use some other computer software to make your plot.

4. Classify
each star as main sequence (M), giant (G), or white dwarf (W) and enter that number in the column.

5. Use the fact that the Sun has an absolute magnitude of 4.5 and scaling from the Stefan-Boltzmann Law to calculate the radius of each star in Solar Radii.