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

Author Question: How can the color index give the star's temperature? What will be an ideal ... (Read 40 times)

gbarreiro

  • Hero Member
  • *****
  • Posts: 566
How can the color index give the star's temperature?
 
  What will be an ideal response?

Question 2

How did Galileo's observations of Venus disprove the Ptolemaic model?
 
  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

cegalasso

  • Sr. Member
  • ****
  • Posts: 295
Answer to Question 1

Color index requires observing the star's brightnesses (magnitudes) through blue and visual filters. By taking the difference between these two magnitudes, the color index is calculated. The color index depends directly on the temperature of the star; the brighter it is in the blue image, the hotter it is.

Answer to Question 2

Ptolemy said that the epicycles for both Venus and Mercury were centered on the Earth-Sun line, so they must always lie between us and the Sun, so would always appear as crescents in the telescope. Galileo found Venus went through the entire phase cycle, proving that she revolved completely around the Sun, as predicted by Copernicus in his heliocentric model.




gbarreiro

  • Member
  • Posts: 566
Reply 2 on: Jul 27, 2018
Wow, this really help


shewald78

  • Member
  • Posts: 340
Reply 3 on: Yesterday
YES! Correct, THANKS for helping me on my review

 

Did you know?

Studies show that systolic blood pressure can be significantly lowered by taking statins. In fact, the higher the patient's baseline blood pressure, the greater the effect of statins on his or her blood pressure.

Did you know?

Hip fractures are the most serious consequences of osteoporosis. The incidence of hip fractures increases with each decade among patients in their 60s to patients in their 90s for both women and men of all populations. Men and women older than 80 years of age show the highest incidence of hip fractures.

Did you know?

Pink eye is a term that refers to conjunctivitis, which is inflammation of the thin, clear membrane (conjunctiva) over the white part of the eye (sclera). It may be triggered by a virus, bacteria, or foreign body in the eye. Antibiotic eye drops alleviate bacterial conjunctivitis, and antihistamine allergy pills or eye drops help control allergic conjunctivitis symptoms.

Did you know?

Intradermal injections are somewhat difficult to correctly administer because the skin layers are so thin that it is easy to accidentally punch through to the deeper subcutaneous layer.

Did you know?

Historic treatments for rheumatoid arthritis have included gold salts, acupuncture, a diet consisting of apples or rhubarb, nutmeg, nettles, bee venom, bracelets made of copper, prayer, rest, tooth extractions, fasting, honey, vitamins, insulin, snow collected on Christmas, magnets, and electric convulsion therapy.

For a complete list of videos, visit our video library