« previous next »

Author Question: Using the technique of main-sequence fitting to determine the distance to a star cluster requires ... (Read 64 times)

Capo

  • Hero Member
  • *****
  • Posts: 545
on: Jul 27, 2018
Using the technique of main-sequence fitting to determine the distance to a star cluster requires that ________.
 
  A) we use ultraviolet and X-ray telescopes
  B) we have telescopes powerful enough to allow us to identify the spectral types of main-sequence stars of many masses in the cluster
  C) the cluster be near enough for us to measure the parallax of its stars
  D) we have a well-calibrated period-luminosity relation for Cepheid variable stars

Question 2

The COBE data allow us to test the isotropy of the universe.
 
  Indicate whether the statement is true or false


yuyiding

  • Sr. Member
  • ****
  • Posts: 357
Reply #1 on: Jul 27, 2018
Answer to Question 1

B

Answer to Question 2

TRUE


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

Though the United States has largely rejected the metric system, it is used for currency, as in 100 pennies = 1 dollar. Previously, the British currency system was used, with measurements such as 12 pence to the shilling, and 20 shillings to the pound.

Did you know?

Though methadone is often used to treat dependency on other opioids, the drug itself can be abused. Crushing or snorting methadone can achieve the opiate "rush" desired by addicts. Improper use such as these can lead to a dangerous dependency on methadone. This drug now accounts for nearly one-third of opioid-related deaths.

Did you know?

Serum cholesterol testing in adults is recommended every 1 to 5 years. People with diabetes and a family history of high cholesterol should be tested even more frequently.

Did you know?

The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."

Did you know?

Cyanide works by making the human body unable to use oxygen.

Yellow Star Grass Yellow Star Grass
Andrea Palladio, Plan of main floor (piano nobile), Villa La Rotunda. Andrea Palladio, Plan of main floor (piano nobile), Villa La Rotunda.
The inverse-square law and its effects. Doubling your distance away from a radioactive material ... The inverse-square law and its effects. Doubling your distance away from a radioactive material ...
Main lymph nodes of the leg Main lymph nodes of the leg
An old set of christmas tree lights have 30 lights, 20.6~ each in a series alignment. Determine ... An old set of christmas tree lights have 30 lights, 20.6~ each in a series alignment. Determine ...
A promissory note for $600.OO dated January 15, 2017. requires an interest payment of $120 00 ... A promissory note for $600.OO dated January 15, 2017. requires an interest payment of $120 00 ...
Video: Hydrogen bonds - role in the body

For a complete list of videos, visit our video library