Question

What can be concluded about the initial mass of a blue main sequence star compared to a red main sequence star?

1) Blue main sequence stars had a greater initial mass.
2) Red main sequence stars had a greater initial mass.
3) Blue main sequence stars have the same initial mass as red main sequence stars.
4) Initial mass comparisons cannot be made between blue and red main sequence stars.

Answer 1

Blue main sequence stars have a greater initial mass compared to red main sequence stars(option 1).

Step-by-step explanation:

Comparing the initial mass of blue main sequence stars to that of red main sequence stars, we can conclude that blue main sequence stars have a greater initial mass(option 1). This is evident through the study of various models of stars which show that the structure of a star in equilibrium that derives its energy from nuclear fusion is determined by its total mass and composition. Specifically, massive stars on the main sequence have high temperatures and luminosities, which are characteristics of blue main sequence stars, while low-mass stars, like red main sequence stars, have lower temperatures and luminosities.

The stellar evolution tracks in the H-R diagram confirm that more massive stars evolve more quickly than their less massive counterparts. Moreover, within a star cluster, more massive stars tend to leave the main sequence earlier and become red giants, while less massive stars remain in the main sequence phase for a longer period. This further indicates that blue main sequence stars must have had a greater initial mass compared to red main sequence stars that still linger on the main sequence.