Accretion disk

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/accretion-disk

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 central objects?Stars, white dwarfs, neutron stars, black holes (stellar-mass and supermassive)
2. How does an accretion disk form around a star or black hole?The disk forms because the gas and dust that fall toward the central object have angular momentum. Instead of dropping straight in, they orbit and flatten into a disk. Viscosity in the disk helps move angular momentum outward, letting the material slowly spiral inward.
3. Why do the inner parts of an accretion disk get so hot?The inner parts of the disk get very hot because the strong gravity and friction between particles heat the gas and dust to millions or billions of degrees Celsius. This hot plasma then shines across the electromagnetic spectrum.

Viscosity: A measure of a fluid's resistance to flow; in accretion disks, it drives angular momentum transport.
Relativistic Jets: Collimated outflows of plasma ejected at speeds close to the speed of light from the vicinity of accreting compact objects.
Active Galactic Nuclei (AGN): Regions at the center of galaxies that emit large amounts of energy, powered by accretion onto a supermassive black hole.