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

Author Question: Which of the following is true of O and B stars? A) Their parallax is too small to measure. B) ... (Read 68 times)

asan beg

  • Hero Member
  • *****
  • Posts: 570
Which of the following is true of O and B stars?
 
  A) Their parallax is too small to measure.
  B) They are not found in associations.
  C) They reveal parts of six spiral arms near the Sun.
  D) Their distances cannot be measured by spectroscopic parallax.

Question 2

The mass of the Milky Way Galaxy can be estimated by:
 
  A) the orbital motions of the stars within the galaxy.
  B) the mass of the planets in the Solar System.
  C) the luminosity of the stars of the neighboring galaxies.
  D) the concept laid down by the spiral density wave theory.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

yasmin

  • Sr. Member
  • ****
  • Posts: 319
Answer to Question 1

A

Answer to Question 2

A



asan beg

  • Hero Member
  • *****
  • Posts: 570
Both answers were spot on, thank you once again



yasmin

  • Sr. Member
  • ****
  • Posts: 319

 

Did you know?

HIV testing reach is still limited. An estimated 40% of people with HIV (more than 14 million) remain undiagnosed and do not know their infection status.

Did you know?

During the twentieth century, a variant of the metric system was used in Russia and France in which the base unit of mass was the tonne. Instead of kilograms, this system used millitonnes (mt).

Did you know?

When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).

Did you know?

Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.

Did you know?

According to the National Institute of Environmental Health Sciences, lung disease is the third leading killer in the United States, responsible for one in seven deaths. It is the leading cause of death among infants under the age of one year.

For a complete list of videos, visit our video library