Clusters and Messier and Binariws

You are asked to return various images and answer a few questions. You MUST place all images in a word processor and include a description of the images with its URL. You do not have to use the suggested URLs that I give you.

Questions

1. Explain why the Sun is stable, i.e. explain how the Sun keeps from collapsing or exploding as long as it is on the main sequence. (Ref 528-529)

2. On page 532 you will find the description of the CNO cycle. Is the Carbon destroyed as the process creates energy? Explain. Why is the CNO only significant for massive stars? What is the dominant energy cycle for our Sun and what percentage of its energy is generated by the CNO cycle?

3. On page 519 you will find the HR diagram for Omega Centarui. Sketch the diagram and explain how its age is determined.

Images

4. Globular clusters contain the first stars to form around our galaxy. Today, there are perhaps 200 such clusters. Return an image of a globular cluster. Include a description of the images and the URL. Some possible URLs are

http://antwrp.gsfc.nasa.gov/apod/ap071115.html

http://antwrp.gsfc.nasa.gov/apod/ap070609.html

http://antwrp.gsfc.nasa.gov/apod/ap070518.html

http://antwrp.gsfc.nasa.gov/apod/ap070419.html

http://antwrp.gsfc.nasa.gov/apod/ap040511.html

5. Galactic or open star clusters are relatively young. These swarms of bright stars are born near the plane of the Milky Way, but their numbers steadily dwindle as cluster members are strewn through the Galaxy by gravitational interactions. Return an image of an open cluster. Include a description of the images and the URL where you located the image. Some possible URLs are

http://antwrp.gsfc.nasa.gov/apod/ap071118.html

http://antwrp.gsfc.nasa.gov/apod/ap040331.html

http://antwrp.gsfc.nasa.gov/apod/ap040222.html

http://antwrp.gsfc.nasa.gov/apod/ap021201.html

http://antwrp.gsfc.nasa.gov/apod/ap031202.html

http://antwrp.gsfc.nasa.gov/apod/ap030107.html

http://antwrp.gsfc.nasa.gov/apod/ap030122.html

6. Planetary nebulae are created at the end of a sun-like star's life as its outer layers expand into space while the star's core shrinks to become a white dwarf. The nebula's main bubble structure is about a light-year across and the glows from the ionized atoms. The central hot white dwarf radiates strongly at ultraviolet wavelengths and powers the expanding nebula's glow. Planetary Nebula offers a glimpse of the fate of our Sun, which should produce its own planetary nebula only about 5 billion years from now. Return an image of a Planetary Nebula. Include a description of the images and the URL where you located the image. Possible URLs are

http://antwrp.gsfc.nasa.gov/apod/ap071014.html

http://antwrp.gsfc.nasa.gov/apod/ap070803.html

http://antwrp.gsfc.nasa.gov/apod/ap070513.html

http://antwrp.gsfc.nasa.gov/apod/ap070223.html

http://antwrp.gsfc.nasa.gov/apod/ap061112.html

http://antwrp.gsfc.nasa.gov/apod/ap060709.html

7. Some massive stars are over 100 times the mass of the sun. These rare and short-lived super-hot stars are characterized by the ejection of mass and strong stellar winds. Three examples are the Pistol star, Eta Carinae, and WR124. Return an image of a massive star. Include a brief description and the URL. Possible URLs are http://antwrp.gsfc.nasa.gov/apod/ap061219.html

http://antwrp.gsfc.nasa.gov/apod/ap060326.html

http://antwrp.gsfc.nasa.gov/apod/ap971008.html

http://antwrp.gsfc.nasa.gov/apod/ap051015.html