25. what is left after a planetary nebula for...
25. what is left after a planetary nebula forms?\na) red dwarf\nb) protostar\nc) white dwarf\nd) neutron star\n26. what do small stars become at the end of their lives?\na) red giants\nb) black holes\nc) red dwarfs\nd) cool white dwarfs\n27. what is the final stage of a massive star?\na) red dwarf\nb) white dwarf\nc) supernova\nd) planet\n28. what can a supernova produce?\na) only dust\nb) nothing\nc) neutron star or black hole\nd) galaxy\n29. what is a constellation?\na) real group of stars\nb) optical illusion\nc) pattern we see in the sky\nd) planet cluster\n30. who first named constellations?\na) nasa\nb) modern scientists\nc) ancient civilizations\nd) aliens\n31. what constellation contains the north star?\na) orion\nb) leo\nc) ursa minor\nd) scorpius\n32. how many official constellations are there today?\na) 12\nb) 36\nc) 88\nd) 100