RSGC
SES4U
SES4U Lab Activity: Wien’s Law
The light from three stars is analyzed. For each star, instruments measure the intensity (brightness)
of light at various wavelengths (colours). The results are summarized below:
STAR A
Wavelength
(nm)
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
STAR B
Intensity
0
10
25
35
45
50
44
38
31
24
20
18
16
14
13
12
11
10
10
9
9
Wavelength
(nm)
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
STAR C
Intensity
0
10
60
100
90
80
72
64
58
53
50
45
40
36
34
32
30
28
26
24
20
Wavelength
(nm)
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
Intensity
0
2
4
5
6
7
8
8
9
9
10
10
9
9
8
7
7
6
6
5
5
1. Use the data above to graph in Excel three data sets of wavelength (x-axis) vs. Intensity (yaxis). On a single graph, have all three curves.
2. Examine the three curves and answer the following:
a. List the stars in order of hottest to coolest.
b. For STAR A, what is the wavelength of light at its maximum emission (λmax)?
c. Use the following equation to find the temperature, T, in Kelvins of STAR A. λmax=
2900000 K nm/T
3. On a separate sheet or on the same graph, sketch a curve of data that might represent a star
that is even cooler than the all three of the above stars.