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 150 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
YES! Correct, THANKS for helping me on my review

JCABRERA33

  • Member
  • Posts: 344
Reply 3 on: Yesterday
Gracias!

« previous next »
 

Did you know?

ACTH levels are normally highest in the early morning (between 6 and 8 A.M.) and lowest in the evening (between 6 and 11 P.M.). Therefore, a doctor who suspects abnormal levels looks for low ACTH in the morning and high ACTH in the evening.

Did you know?

The training of an anesthesiologist typically requires four years of college, 4 years of medical school, 1 year of internship, and 3 years of residency.

Did you know?

Walt Disney helped combat malaria by making an animated film in 1943 called The Winged Scourge. This short film starred the seven dwarfs and taught children that mosquitos transmit malaria, which is a very bad disease. It advocated the killing of mosquitos to stop the disease.

Did you know?

People who have myopia, or nearsightedness, are not able to see objects at a distance but only up close. It occurs when the cornea is either curved too steeply, the eye is too long, or both. This condition is progressive and worsens with time. More than 100 million people in the United States are nearsighted, but only 20% of those are born with the condition. Diet, eye exercise, drug therapy, and corrective lenses can all help manage nearsightedness.

Did you know?

Fewer than 10% of babies are born on their exact due dates, 50% are born within 1 week of the due date, and 90% are born within 2 weeks of the date.

Structure of eudicot and monocot seeds Structure of eudicot and monocot seeds
X-Ray Crystallography Helped Reveal the Structure of DNA X-Ray Crystallography Helped Reveal the Structure of DNA
Transfer RNA (tRNA) Structure Transfer RNA (tRNA) Structure
Structure of an animal cell Structure of an animal cell
Cumulative change for six personality-trait domains across the life course show distinct patterns. Cumulative change for six personality-trait domains across the life course show distinct patterns.
The structure of sphingosine The structure of sphingosine
Video: Blood Pressure Measurement

For a complete list of videos, visit our video library