Author Question: The visible parts of galaxies contribute about 10 percent of the critical density of the universe. ... (Read 33 times)

Jipu 123 · **on:** Jul 27, 2018

The visible parts of galaxies contribute about 10 percent of the critical density of the universe.

Indicate whether the statement is true or false

Question 2

Answer each of the following questions for our local sky.

A. Where is the north celestial pole in our sky?
B. Is Polaris a circumpolar star in our sky? Explain.
C. Describe the meridian in our sky.
D. Describe the celestial equator in our sky.

lauravaras · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

FALSE

Answer to Question 2

A. Answers will vary with latitude; here is a sample for 40N: The north celestial pole appears at an altitude of 40, in the direction due north.
B. Yes, for any location in the Northern Hemisphere; no, for any location in the Southern Hemisphere. Polaris is circumpolar because it never rises or sets in our sky. It makes a daily circle, less than 1 in radius, around the north celestial pole.
C. The meridian is a half-circle that stretches from the due south point on the horizon, through the zenith, to the due north point on the horizon.
D. Answers will vary with latitude; here is a sample answer for 40N: The celestial equator is a half-circle that stretches from the due east point on the horizon, through an altitude of 50 due south, to the due west point on the horizon.