Question

List the six stages, in order, a massive star undergoes and its lifespan starting with NEBUL and ending with neutron star

Answer 1

i) A star is formed from an accumulation of high density region called Nebula which then condenses to form a massive collection of gas and dust contracting under its own gravity.

ii) The temperature of this condensing region will start to rise up until it glows to form a Protostar. In this stage of formation nuclear reactions starts taking place where hydrogen is fused into helium thereby producing fuel.

iii) Due to the generated fuel it starts producing energy and thereby making it glow even more. It has now become a Main sequence star.

iv) The star now continues to glow with all the fuel and stars expanding outwards thereby becoming a Red Supergiant.

v) With the fuel coming to an end the nuclear reactions are now not sufficient to hold down the gravity of the star itself. As a result the star collapses into its own core and due to the huge density of mass confined in such a small location it blows out into an expansion causing what is called a Supernova. This explosion produces a huge amount of energy in the shock wave which tears apart the outer layers.

vi) If the core survives the remnants of a Supernova it contracts into a dense small mass called the Neutron Star. It consists of mainly close packed neutrons.