Ch23 - Assignment Chapter 23 Class Astronomy I Date November 19th 2007 Review Questions 1 Because Milky Way completely encircles us all the stars

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

View Full Document Right Arrow Icon
Assignment: Chapter 23 Class: Astronomy I Date: November 19th, 2007 Review Questions 1. Because Milky Way completely encircles us, all the stars in the sky are part of an enormous disk of stars, and we see them as a bright band. 2. Interstellar extinction only allowed us to see the nearest stars in the Galaxy. Hence, we had no idea of either the enormous size of the Galaxy or of the vast number of stars concentrated around the center. 3. Because globular clusters are located above the Galactic plane, we were still able to see them through interstellar dust. 4. RR Lyrae variables are very similar to the Cepheid variables, but these have shorter pulsation periods and lower peak luminosities. Since these are so commonly found in glublar clusters, Shapley was able to determine the distances to the globular clusters using period-luminosity relationship. 5. The longer the wavelength, the farther radiation can travel through interstellar dust without being scattered or absorbed. Hence, infrared radiation can traverse the Galaxy freely. 6. The stars in the disk are mostly young, metal-rich, Population I stars like the Sun. The presence of these astronomically young stars shows that there must be active star formation in the galactic disk. 7. No O and B stars are present in the halo, because star formation ceased there long ago. 8. When the spin of the electron changes its orientation from the high-energy to low- energy, this spin-flip transition emits 21-cm radio emission. 9.The H II regions would be more abundant in the Milky Way.
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

Ch23 - Assignment Chapter 23 Class Astronomy I Date November 19th 2007 Review Questions 1 Because Milky Way completely encircles us all the stars

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