Solar radius

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/solar-radius

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 scientific unit?Solar radius (R⊙) is a standard astronomical unit for stellar dimensions
2. What is the measured value?695,700 kilometers (432,300 miles)
3. How big is the Sun compared to Earth?The Sun’s radius is about 695,700 kilometers, which is roughly 109 times the radius of Earth, so it is much larger than our planet.
4. How do scientists measure the solar radius?Scientists use careful observations and calculations of the Sun’s light and size, and they look at the point where the Sun’s atmosphere becomes transparent to determine the radius.

Solar Radius (R⊙): A fundamental astronomical unit of length, equal to the Sun's radius, used for measuring stellar sizes.
Photosphere: The visible surface layer of a star, from which most of its light is radiated.
Optical Depth: A measure of how opaque a substance is to radiation, indicating how far light can penetrate.
Oblateness: The degree to which a celestial body is flattened at its poles and bulges at its equator due to rotation.