Nucleus of the Milky Way Galaxy

What is the nucleus of a galaxy also called?

• Black hole

• Star cluster

• Galactic core

• Central bulge

What is Sagittarius A*?

• A star

• A supermassive black hole

• A planet

• A galaxy

What type of galaxy is the Milky Way?

• Lenticular galaxy

• Barred spiral galaxy

• Irregular galaxy

• Elliptical galaxy

Why can't we see the nucleus of our galaxy with visible light?

• It's too bright

• It's blocked by space dust and gas

• It's moving too fast

• It's too far away

What type of vision do we use to see through the dust in the galaxy?

• Gamma-ray vision

• Radio and infrared vision

• Microwave vision

• Ultraviolet vision

What is the size of Sagittarius A*?

• One light-year in diameter

• One parsec in diameter

• One kilometer in diameter

• One astronomical unit in diameter

How many solar masses does Sagittarius A* have?

• Four million solar masses

• Two million solar masses

• Ten million solar masses

• One million solar masses

What is the main reason Sagittarius A* is considered dormant?

• It has no accretion disk

• It is too small

• It is too far away

• It emits no energy

What happens to the dust around the crowded stars in the nucleus?

• It cools down

• It emits strong infrared radiation

• It disappears

• It forms new stars

How many photons from the center of our galaxy reach Earth?

• One trillion photons

• One million photons

• One thousand photons

• One photon