Be star

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/be-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 spectral type and emission?B-type stars exhibiting hydrogen emission lines, indicative of a circumstellar disk
2. What is the rotation velocity?Often rotate at a significant fraction of their critical (breakup) velocity
3. What makes a Be star different from other stars?Be stars are hot, bright B-type stars that have a disk of gas around them, which shows up as hydrogen emission lines in their light.
4. Why do Be stars have a disk of gas around them?Their fast spinning pushes material off the equator, and the gas settles into a flattened disk that orbits the star.

Keplerian disk: A disk where orbital velocity decreases with distance from the central object, following Kepler's laws.
Breakup velocity: The maximum rotation speed a star can achieve before its equatorial material is ejected.
OB association: A loosely bound group of massive, hot O and B-type stars found in regions of active star formation.
Spectroscopic binary: A binary star system whose orbital motion is detected by observing Doppler shifts in its spectral lines.