LIFECYLE OFLARGE STARS
STAGE 1: NEBULAThere are numerous giganticclouds of dust and gas(mostly hydrogen) spreadacross freezing coldinterstellar space. They arecalled “Nebulae”.
STAGE 2:PROTOSTAR
The cloud of dust and gasgathers together due to
gravity by virtue of its mass.At the center of this cloud
forms, what is known asa “Protostar”.
STAGE 3: MAINSEQUENCE STARA main sequence star is agigantic sphere in space,fusing hydrogen into heliuminside its core and using thisenergy released in the fusionreaction to counteract its owngravity (which is trying tocrush it).
STAGE 4: REDSUPERGIANT
Due to energy released inthe fusion reaction taking
place at the layers justabove the core, the
outermost layers of the starexpand and the star
becomes what is known asa “Red Supergiant”.
LIFECYLE OFLARGE STARSCONTINUED
STAGE 5:SUPERNOVA A supernova is an explosionin which a star explodesand expels its outer layersleaving a core behind tocollapse in on itself.
STAGE 6 A:NEUTRON STAR
A neutron star is a core of astar after the supernova
which can have a mass up to2.17 solar masses. They are
very dense as the whole massof the star is compressed to
the size of a city.
STAGE 6 B:BLACK HOLE If the mass of theprogenitor star is more than10-29 solar masses its corecollapses into itself andforms what is known as a"Black hole" after thesupernova explosion.
SOURCES:
SPACEPLACE.NASA.GOVNASA.GOV