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

Author Question: Why are all spiral tracers young? What will be an ideal ... (Read 59 times)

magmichele12

  • Hero Member
  • *****
  • Posts: 559
on: Jul 27, 2018
Why are all spiral tracers young?
 
  What will be an ideal response?

Question 2

Most stars generate their energy by the thermonuclear fusion of ___________________ _ to form ___________________ _.
 
  Fill in the blank(s) with correct word


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

sierrahalpin

  • Sr. Member
  • ****
  • Posts: 329
Reply #1 on: Jul 27, 2018
Answer to Question 1

Spiral tracers are young objects, formed recently, astronomically speaking. O stars, for example, live for only a few million years. Their typical orbital velocity is about 200 km/s, so they cannot move more than about 500 pc in their lifetimes. This is less than the width of a spiral arm. Because they don't live long enough to move away from the spiral arms, they must have formed there.

Answer to Question 2

hydrogen; helium


magmichele12

  • Member
  • Posts: 559
Reply 2 on: Jul 27, 2018
Excellent

chereeb

  • Member
  • Posts: 326
Reply 3 on: Yesterday
Gracias!

« previous next »
 

Did you know?

In the United States, congenital cytomegalovirus causes one child to become disabled almost every hour. CMV is the leading preventable viral cause of development disability in newborns. These disabilities include hearing or vision loss, and cerebral palsy.

Did you know?

Acute bronchitis is an inflammation of the breathing tubes (bronchi), which causes increased mucus production and other changes. It is usually caused by bacteria or viruses, can be serious in people who have pulmonary or cardiac diseases, and can lead to pneumonia.

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?

Multiple sclerosis is a condition wherein the body's nervous system is weakened by an autoimmune reaction that attacks the myelin sheaths of neurons.

Did you know?

Drugs are in development that may cure asthma and hay fever once and for all. They target leukotrienes, which are known to cause tightening of the air passages in the lungs and increase mucus productions in nasal passages.

Charging young leopard Charging young leopard
A young elephant in Zimbabwe. A young elephant in Zimbabwe.
These young adults look forward to a life together as they celebrate their wedding These young adults look forward to a life together as they celebrate their wedding
Shope’s Model of Young Driver Crash Risks The model shows that many factors contribute to crash ris Shope’s Model of Young Driver Crash Risks The model shows that many factors contribute to crash ris
In 1879 an army officer founded the Carlisle School in Pennsylvania to “civilize” young Indians. The In 1879 an army officer founded the Carlisle School in Pennsylvania to “civilize” young Indians. The
The Number of Children Americans Think Are Ideal The Number of Children Americans Think Are Ideal
Video: Power Supply Polyacrylamide Gel Protein Sample

For a complete list of videos, visit our video library