This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Explain how Edwin Hubble used Cepheid variables to change our view of the structure of the universe. ... (Read 148 times)

cnetterville

  • Hero Member
  • *****
  • Posts: 547
on: Jul 14, 2018
Explain how Edwin Hubble used Cepheid variables to change our view of the structure of the universe.
 
  What will be an ideal response?

Question 2

How does the Sun compare in size and brightness to other main-sequence stars?
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

jxjsniuniu

  • Sr. Member
  • ****
  • Posts: 343
Reply #1 on: Jul 14, 2018
Answer to Question 1

Cepheid variables are extremely bright variable stars that increase and decrease in brightness in a repetitive cycle. This group of stars is significant because their true brightness, called absolute magnitude, can be determined by knowing the rate at which they pulsate. When the absolute magnitude of a star is compared to its observed brightness, a reliable approximation of distance can be established. Thus, Cepheid variables are important because they can be used to measure large astronomical distances. Hubble observed the Andromeda galaxy, beyond the Milky Way, and used his observations to determine that the universe extended far beyond the limits of our imagination.

Answer to Question 2

It is a medium-sized, middle-of-the-road main sequence star.


cnetterville

  • Member
  • Posts: 547
Reply 2 on: Jul 14, 2018
Excellent

LegendaryAnswers

  • Member
  • Posts: 341
Reply 3 on: Yesterday
Great answer, keep it coming :)

« previous next »
 

Did you know?

In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).

Did you know?

Certain rare plants containing cyanide include apricot pits and a type of potato called cassava. Fortunately, only chronic or massive ingestion of any of these plants can lead to serious poisoning.

Did you know?

Each year in the United States, there are approximately six million pregnancies. This means that at any one time, about 4% of women in the United States are pregnant.

Did you know?

The Centers for Disease Control and Prevention has released reports detailing the deaths of infants (younger than 1 year of age) who died after being given cold and cough medications. This underscores the importance of educating parents that children younger than 2 years of age should never be given over-the-counter cold and cough medications without consulting their physicians.

Did you know?

Before a vaccine is licensed in the USA, the Food and Drug Administration (FDA) reviews it for safety and effectiveness. The CDC then reviews all studies again, as well as the American Academy of Pediatrics and the American Academy of Family Physicians. Every lot of vaccine is tested before administration to the public, and the FDA regularly inspects vaccine manufacturers' facilities.

Chemical structure of lipids. Chemical structure of lipids.
Structure of the sliding clamp Structure of the sliding clamp
Amino Acid Structure Amino Acid Structure
Development of the Eyes and Ears: External View - 28 days Embryo Development of the Eyes and Ears: External View - 28 days Embryo
The Thoracic Vertebrae: Right Lateral View of Vertebra The Thoracic Vertebrae: Right Lateral View of Vertebra
Video: Hydrogen bonds vs. Ionic bond

For a complete list of videos, visit our video library