Galaxies

4. the galaxy that includes our Solar System
6. astronomical object held by gravity
9. a luminous giant star of low or intermediate mass in a late phase of stellar evolution.
10. collapsed core of a massive supergiant star
14. flat disk
15. a satellite galaxy of the Milky Way
17. barred spiral galaxy with diameter of about 220,000 ly
19. a powerful and luminous stellar explosion

1. circular/elongated
2. a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars
3. a radio galaxy, and one of the strongest radio sources in the sky.
5. what stars are made of
7. a stellar core remnant composed mostly of electron-degenerate matter
8. largest stars in the universe in terms of volume
11. no shape
12. a star that is larger than eight solar masses during its regular main sequence lifetime
13. a region of spacetime where gravity is so strong that nothing – no particles or even electromagnetic radiation such as light – can escape from it
16. a disputed dwarf irregular galaxy in the Local Group
18. spends most of its time on the main sequence as an orange, yellow, or blue-white dwarf star.