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

Author Question: What factors are important when trying to classify a spiral galaxy? a. amount of dust and gas in ... (Read 48 times)

lracut11

  • Hero Member
  • *****
  • Posts: 536
on: Jul 27, 2018
What factors are important when trying to classify a spiral galaxy?
 
  a. amount of dust and gas in the galaxy
  b. structure of the spiral arms
  c. size of the central region
  d. All of the other choices are important.

Question 2

Why are reflection nebulae blue in color?
 
  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

Viet Thy

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

d

Answer to Question 2

Reflection nebulae look blue for the same reason the sky looks blue. Short wavelengths scatter more easily than long wavelengths, so blue photons are scattered. The blue color shows that the dust particles must be very small to preferentially scatter blue photons.


lracut11

  • Member
  • Posts: 536
Reply 2 on: Jul 27, 2018
:D TYSM

carlsona147

  • Member
  • Posts: 341
Reply 3 on: Yesterday
YES! Correct, THANKS for helping me on my review

« previous next »
 

Did you know?

If all the neurons in the human body were lined up, they would stretch more than 600 miles.

Did you know?

Throughout history, plants containing cardiac steroids have been used as heart drugs and as poisons (e.g., in arrows used in combat), emetics, and diuretics.

Did you know?

Prostaglandins were first isolated from human semen in Sweden in the 1930s. They were so named because the researcher thought that they came from the prostate gland. In fact, prostaglandins exist and are synthesized in almost every cell of the body.

Did you know?

In 1886, William Bates reported on the discovery of a substance produced by the adrenal gland that turned out to be epinephrine (adrenaline). In 1904, this drug was first artificially synthesized by Friedrich Stolz.

Did you know?

Liver spots have nothing whatsoever to do with the liver. They are a type of freckles commonly seen in older adults who have been out in the sun without sufficient sunscreen.

Environmental factors restricting the distribution of Chthamalus to the upper intertidal zone. Environmental factors restricting the distribution of Chthamalus to the upper intertidal zone.
ABO Blood Reactions Are Important in Transfusions ABO Blood Reactions Are Important in Transfusions
Factors influencing character of respirations Factors influencing character of respirations
How Orbital Eccentricity Changes the Amount of Solar Radiation Earth Receives How Orbital Eccentricity Changes the Amount of Solar Radiation Earth Receives
How to classify whether an equation is linear, quadratic, or cubic How to classify whether an equation is linear, quadratic, or cubic
When exercising outdoors, especially on a hot, sunny day, it is important to stay adequately hydrate When exercising outdoors, especially on a hot, sunny day, it is important to stay adequately hydrate
Video: Membrane transport proteins - pores, gated channels and pumps

For a complete list of videos, visit our video library