Introduction
The year 2009 was the International Year of Astronomy, commemorating the 400th anniversary of the following two important moments in the history of astronomy:
- Galileo Galilei’s use of a telescope to study the skies, which led some astronomers to shift their thinking from a geocentric view of our world to a solar centric view.
- The publication of Johannes Kepler’s groundbreaking work “Astronomia Nova,” which proved by scientific observation, what other astronomers had only conjectured, that the Earth revolves around the sun and not vice versa.
We are going to use the latest form of a telescope, the WorldWide Telescope, to help us conduct our own astronomical research. WorldWide Telescope is visualization software that enables a computer to function as a virtual telescope. As you’ll discover, it brings together imagery from the best ground and space-based telescopes in the world for an exciting and interactive exploration of the universe. We are going to use it to explore the systems, lifecycle, and characteristics of stars.
Can anyone define a star?
A star is a massive sphere of hot glowing gas or plasma that is held together by its own gravity. Stars are made chiefly of hydrogen and a smaller amount of helium. Even the most abundant of the other elements present in stars—oxygen, carbon, neon, and nitrogen—exist in very small quantities.
A star has five main characteristics:
- Brightness (magnitude and luminosity)
- Color
- Surface temperature
- Size
- Mass (amount of matter)
In our tour we are going to cover all five of these characteristics and some of the complex ways they relate to one another. As we take Step 2 of the tour, list all five of these on the Student Handout and take notes on them. You will need to include references to at least three of these five characteristics of stars in your final presentation. Later, you will research one aspect of the stars that interests you and use WWT to create a guided tour to teach the rest of the class what you have learned.
Note: information and references taken from Microsoft Encarta Reference 2009 and Worldbook@NASA.