Answer:1.) it is so bright because it is the closest star
2.) apparent magnitude is a estimate
3.) red, orange, yellow, green, white and blue with red being the coolest and blue being the hottest
4.)Brown Dwarf, Red Dwarf, Yellow Dwarf,Blue Giant,Orange Giant,Red Giant, Blue Supergiant,Blue Hypergiant,Red Supergiant,Red Hypergiant
Step-by-step explanation: