This topic contains a solution. Click here to go to the answer

Author Question: How do we know that a hot main sequence star (and not some other kind of star) is embedded in a ... (Read 31 times)

ap345

  • Hero Member
  • *****
  • Posts: 537
How do we know that a hot main sequence star (and not some other kind of star) is embedded in a cloud of interstellar gas?
 
  What will be an ideal response?

Question 2

What are the similarities and differences between the Kelvin and Fahrenheit temperature scales? Identify the freezing point of water on both scales.
 
  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

Awesome

  • Sr. Member
  • ****
  • Posts: 280
Answer to Question 1

Except for white dwarfs, all hot stars are very luminous. The large amount of ultraviolet light produced by them will ionize any gas in their vicinity and produce an HII region. The visible light from the HII region's emission spectrum tells us of the presence of the gas.

Answer to Question 2

The Fahrenheit scale is an archaic scale that has no obvious starting point. The Kelvin scale was devised to begin at the lowest possible temperature in the universe. In Fahrenheit the freezing point of water is 32, in Kelvin it's 273.





 

Did you know?

Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.

Did you know?

According to the CDC, approximately 31.7% of the U.S. population has high low-density lipoprotein (LDL) or "bad cholesterol" levels.

Did you know?

There can actually be a 25-hour time difference between certain locations in the world. The International Date Line passes between the islands of Samoa and American Samoa. It is not a straight line, but "zig-zags" around various island chains. Therefore, Samoa and nearby islands have one date, while American Samoa and nearby islands are one day behind. Daylight saving time is used in some islands, but not in others—further shifting the hours out of sync with natural time.

Did you know?

The strongest synthetic topical retinoid drug available, tazarotene, is used to treat sun-damaged skin, acne, and psoriasis.

Did you know?

Approximately 15–25% of recognized pregnancies end in miscarriage. However, many miscarriages often occur before a woman even knows she is pregnant.

For a complete list of videos, visit our video library