Apparent magnitude

High school (ages 12+)
Space & Astronomy

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/apparent-magnitude

1. What is the modern definition?
2. What is the key influencing factors?
3. Why does a smaller magnitude number mean a brighter star?
4. How many times brighter is a magnitude 2 star compared to a magnitude 3 star?

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the modern definition?Mathematically defined by Norman Pogson in 1856 to precisely match historical classifications
2. What is the key influencing factors?Intrinsic luminosity, distance from the observer, and interstellar extinction
3. Why does a smaller magnitude number mean a brighter star?The scale is inverse; brighter stars get lower numbers. A difference of one magnitude means the star is about 2.5 times brighter.
4. How many times brighter is a magnitude 2 star compared to a magnitude 3 star?A magnitude 2 star is about 2.5 times brighter than a magnitude 3 star.

Apparent Magnitude (m): A logarithmic measure of the brightness of a celestial object as seen from Earth.
Inverse Logarithmic Scale: A scale where higher brightness corresponds to lower numerical values.
Photometry: The scientific process of measuring the brightness of astronomical objects.
Interstellar Extinction: The dimming of light from celestial sources due to absorption and scattering by interstellar dust and gas.