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 104 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?

Nearly 31 million adults in America have a total cholesterol level that is more than 240 mg per dL.

Did you know?

Only one in 10 cancer deaths is caused by the primary tumor. The vast majority of cancer mortality is caused by cells breaking away from the main tumor and metastasizing to other parts of the body, such as the brain, bones, or liver.

Did you know?

Approximately 500,000 babies are born each year in the United States to teenage mothers.

Did you know?

Historic treatments for rheumatoid arthritis have included gold salts, acupuncture, a diet consisting of apples or rhubarb, nutmeg, nettles, bee venom, bracelets made of copper, prayer, rest, tooth extractions, fasting, honey, vitamins, insulin, snow collected on Christmas, magnets, and electric convulsion therapy.

Did you know?

Asthma attacks and symptoms usually get started by specific triggers (such as viruses, allergies, gases, and air particles). You should talk to your doctor about these triggers and find ways to avoid or get rid of them.

Four main models that describe the relationship between ecosystem function and biodiversity. Four main models that describe the relationship between ecosystem function and biodiversity.
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
During a total solar eclipse, the solar corona can be seen with the naked eye, during the brief peri During a total solar eclipse, the solar corona can be seen with the naked eye, during the brief peri
Attachment is a close emotional relationship. Attachment is a close emotional relationship.
Graph showing the relationship between the freezing point of the coolant and the percentage of ... Graph showing the relationship between the freezing point of the coolant and the percentage of ...
Anthropocene Period Anthropocene Period
Video: Stomach peristalsis & Enterogastric reflex

For a complete list of videos, visit our video library