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

Author Question: How did Harlow Shapley use the period-luminosity relationship of RR Lyrae variables to determine the ... (Read 48 times)

luminitza

  • Hero Member
  • *****
  • Posts: 555
on: Jul 27, 2018
How did Harlow Shapley use the period-luminosity relationship of RR Lyrae variables to determine the size of the Milky Way galaxy?
 
  a. He determined the proper motion of globular clusters in the outer disk of the galaxy.
  b. He found the distances to individual variables free floating in the halo.
  c. He found the distances to open clusters found throughout the disk of the galaxy.
  d. He found the distances to globular clusters distributed about the center of the galaxy.

Question 2

What causes the outward gas pressure that balances the inward pull of gravity in a main-sequence star?
 
  a. the rapid outward flow of gas
  b. the rapid inward flow of the gas
  c. the high temperature of the gas
  d. the high density of the gas
  e. the high temperature and the high density of the gas


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

aruss1303

  • Sr. Member
  • ****
  • Posts: 314
Reply #1 on: Jul 27, 2018
Answer to Question 1

d

Answer to Question 2

e


luminitza

  • Hero Member
  • *****
  • Posts: 555
Reply #2 on: Jul 27, 2018
Thank you!


aruss1303

  • Sr. Member
  • ****
  • Posts: 314
Reply #3 on: Jul 27, 2018
Always glad to help...


« previous next »
 

Did you know?

About one in five American adults and teenagers have had a genital herpes infection—and most of them don't know it. People with genital herpes have at least twice the risk of becoming infected with HIV if exposed to it than those people who do not have genital herpes.

Did you know?

During pregnancy, a woman is more likely to experience bleeding gums and nosebleeds caused by hormonal changes that increase blood flow to the mouth and nose.

Did you know?

Cocaine was isolated in 1860 and first used as a local anesthetic in 1884. Its first clinical use was by Sigmund Freud to wean a patient from morphine addiction. The fictional character Sherlock Holmes was supposed to be addicted to cocaine by injection.

Did you know?

On average, the stomach produces 2 L of hydrochloric acid per day.

Did you know?

The average human gut is home to perhaps 500 to 1,000 different species of bacteria.

Mars's average distance from the Sun is roughly 230 million km (1.5 AU) and its orbital period Mars's average distance from the Sun is roughly 230 million km (1.5 AU) and its orbital period
Synodic Period Synodic Period
Model of the GABA Receptor–Chloride Channel Molecules in Relationship to Antiseizure Pharmacotherapy Model of the GABA Receptor–Chloride Channel Molecules in Relationship to Antiseizure Pharmacotherapy
Data from more than 22,000 men over the age of 40, showing the relationship between birth weight and ... Data from more than 22,000 men over the age of 40, showing the relationship between birth weight and ...
Triassic Period Triassic Period
Relationship between Income Inequality and the Desired Tax Rate Relationship between Income Inequality and the Desired Tax Rate
Video: Digestive System Animation

For a complete list of videos, visit our video library