Ch19 - Assignment: Chapter 19 Class: Astronomy I Date:...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Assignment: Chapter 19 Class: Astronomy I Date: November 5 th , 2007 Review Questions 1. Over the past 4.56 x 10 9 years, thermonuclear reactions at the core have depleted hydrogen in the core and increased the amount of helium in the core. 2. The inner regions of the Sun are denser now than it was 4.56 billion years ago because the Sun converted more hydrogen into helium. The outer regions of the Sun are less dense now than it was 4.56 billion years ago. 3. Red dwarfs are small, red color stars that have low surface temperature. They take up about 85% of all stars in the Milky Way Galaxy. Red dwarfs have convection cells of rising and falling gas that extend throughout the star’s volume and penetrate into the core. 4. High-mass stars have short main-sequence lifetimes because they are also very luminous. To emit energy so rapidly, these stars must be depleting hydrogen in their cores at a prodigious rate. 5. By studying the stages of these stars, astronomers can deduce that our Sun has about 7 x 10 9 years remaining in its main-sequence stage. 6. 7 billion years from now, our Sun will finish the process of thermonuclear reactions. As the Sun’s core contracts, its atmosphere will expand to envelop Mercury and perhaps reach to the orbit of Venus. Our red-giant Sun will have swollen to a diameter of about 1 AU-roughly 100 times larger than its present
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/25/2008 for the course ASTRON 1 taught by Professor Jsepikas during the Winter '07 term at Pasadena City College.

Page1 / 2

Ch19 - Assignment: Chapter 19 Class: Astronomy I Date:...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online