Stars, Galaxy and Milky way

16. Which of the following is not a type of galaxy?
a) Elliptical
b) Spiral
c) Irregular
d) Tetrahedral

17. What is the name of the supermassive black hole at the center of the Milky Way?
a) Sagittarius A*
b) Andromeda B*
c) The Black Knight
d) The Void

18. What is the nearest galaxy to the Milky Way?
a) Andromeda Galaxy
b) Triangulum Galaxy
c) Whirlpool Galaxy
d) Sombrero Galaxy

19. What is the name of the constellation in which the North Star (Polaris) is located?
a) Ursa Major
b) Orion
c) Cassiopeia
d) Leo

20. What is the name of the process by which stars convert hydrogen into helium in their cores?
a) Nuclear fission
b) Nuclear fusion
c) Nuclear decay
d) Nuclear fusion and fission