Classifying Galaxies
Pretend that you are an astronomer working shortly after Edwin Hubble made his startling
discovery. Now that you know the "nebulae" are actually other galaxies like our own,
you must come up with a way to classify the
galaxies.
Exercise 1:
Look at the following galaxies. Divide them into groups
based on features they have in common. There is no set number of
groups.
Click one of the links in the table below to use the
Get Fields tool to look up each galaxy. You will see a
picture of the field the galaxy is in. Because galaxies tend to cluster together, some of the
fields have more than one large and interesting galaxy. In all the other frames,
the largest galaxy should be obvious. When you click another link, the new
field will appear in the same window. You may want to print the fields out,
so you can compare the galaxies side-by-side.
Use this SkyServer workbook to keep track of your groups.
Run |
Camcol |
Field |
752 |
1 |
244 |
2662 |
4 |
243 |
752 |
1 |
331 |
1737 |
6 |
11 |
756 |
4 |
198 |
2738 |
2 |
196 |
752 |
1 |
432 |
3325 |
3 |
319 |
3325 |
2 |
216 |
3325 |
2 |
215 (just left of center) |
3325 |
3 |
230 (2 galaxies) |
2738 |
3 |
122 (2 nice galaxies) |
3325 |
3 |
352 |
3325 |
1 |
356 |
3325 |
1 |
359 |
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Now, find another group and partner up with them to compare your results.
Question 1: Do you have
the same number of galaxy classes? If not, what distinctions
did one group draw that the other did not? |
Question 2: What do your classification systems have in
common? What makes them different? |
Question 3: Try to
combine the best features of each classification system. Repeat
Exercise 1 with your new system. |
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