A Web-Based Stellar Astronomical Treasure Hunt
A Web-Based Stellar Astronomical Treasure HuntWe are going to cover the Milky Way Galaxy in class: how it formed, what the parts of it are, where objects are generally found, and how we know distances within it. This web-based activity will offer a brief introduction to stars, terms we use to discuss their characteristics, their evolution, and their death. As part of this activity, you will be visiting web sites that have information on all of the objects that you one day may be able to observe.
Visit the following websites:
There are some topics here we may have already touched on, such as "Colors" and Brightnesses." There are also lots of new ones. Start with the link titles "Defining a star" and make sure you know what a star actually is by answering the following question:
1. What is a star exactly?
Now, click on "Brightnesses"
2. What is the magnitude of the faintest stars we can see with the naked eye?
3. Why do stars appear as points in the sky (especially if we were to view them while we were in outer space)?
4. We see luminous stars that are far away. How far away is this limit?
(Don't worry about absolute magnitude, parallax, or parsecs mentioned here.)
Click on "Classes of stars," and answer the following questions:
5. What are main sequence stars actively doing in their cores?
6. How hot are the hottest stars--the "O" stars? How 'cool' are the coolest stars--the "T" stars?
7. One of the stars we know is Vega. Click on the Vega link given in this paragraph. How far away is Vega? Is it like our Sun, or different? How so?
8. Out of the 48 brightest stars list, find your favorite and summarize the information about it in a short paragraph.
Return to http://www.astro.uiuc.edu/~kaler/sow/star_intro.html and click on "Birth."
9. Summarize how stars form in one big, complete, complex sentence (in your own words).
M8: Lagoon Nebula
M16: Eagle Nebula
M17: Majestic Swan Nebula
M20: Trifid Nebula
10. The above 4 websites highlight star forming regions. Examine the web pages. List 2 things that star forming regions have in common. Name 1 thing that is different between 2 of the above star forming regions.
11. What are they? Why are they of great interest for astrophysicists?
12. In the evidence gathered by observing lots of open clusters and studying their properties, why do we believe our ideas about how stars evolve are on a solid theoretical basis?
13. Go to the above web site and read down a bit. Why is the distribution of globular clusters concentrated in the constellations of Sagittarius, Scorpius, and Ophiuchus? What do astronomers think is significant about the globular cluster M54?
14. Some globular clusters (13 of them) are on the opposite side of the Sun from the center of the Milky Way. Where do we think they may have originated?
15. Why do we think the stars in globular clusters are extremely old? That is, what is the evidence that we are interpreting as meaning "old" as the Galaxy?
Once a star runs out of hydrogen to fuse in its core (only the core gets involved in the generation of energy at this stage), it's on its way to death. The Sun will eventually turn into a red giant. Click on Giant stars from "The Natures of the Stars" page.
16. How much larger than the Sun are giant stars?
Globular clusters are filled with old, red-giant stars. These are stars that are extremely old, and which are on their way to certain death (they just take a much, much longer time than humans to die). Go to:
17. Click on Polaris. Polaris is a bright-giant star and is in a class of variable stars. What is the period of Polaris (this is towards the end of the information)? What do astronomers think is happening?
18. Find information on the planetary nebulae listed below. Summarize in one sentence what planetary nebulae are. What is one way the planetary nebulae differ? How are they the same?
M27 -- Dumbbell Nebula
M57 -- The Ring Nebula
NGC 6543 -- Cat's Eye Nebula
NGC 7009 the Saturn Nebula
NGC 7662: Blue Snowball Nebula
19. Pick one of these planetary nebulae. How far away is it? Is the distance certain or uncertain? Explain.
20. How old is the nebula you chose? Write a couple of sentences about what interests you the most about this nebula.
You should also go to http://www.astro.washington.edu/balick/WFPC2/index.html Prof. Balick, chair of the Astronomy Dept., is one of the leaders in studying planetary nebulae. Skim the information further on down this page, as Dr. Balick gives the future of the Sun and solar system.
21. Find the paragraph on white dwarfs and summarize in one sentence what white dwarfs are.
M31 -- Andromeda Galaxy
M32 -- Satellite Galaxy to Andromeda
M33 -- Triangulum Galaxy
M51 -- Whirlpool Galaxy
M64 -- Black-eye Galaxy
M101 -- Pinwheel Galaxy
NGC 4631
22. Summarize your overall impression of these galaxies, and write down one question that you would like to pursue in the near future.