Based on initial size and chemical composition a star will enter a band on the HR diagram as a mains sequence star. Stars on the main sequence are in equilibrium from thermal pressure trying to enlarge the star and gravitational pressure trying to collapse the star. Stars on the main sequence range from massive hot blue-white stars to much less massive red stars.
above the main-sequence stars
The lower right part of the main sequence in the Hertzsprung-Russell diagram contains the stars that took the longest to reach the main sequence. These stars are low mass and cool, so they undergo a longer contraction phase before they start fusing hydrogen in their cores and settle onto the main sequence.
The main sequence stars on the Hertzsprung-Russell diagram that are least massive are the red dwarfs. These stars have low masses compared to other main sequence stars like our sun. They are cooler and fainter, making them difficult to observe compared to more massive stars.
A main-sequence star is one that is along a curve where the majority of stars are located, when plotted in an H-R diagram. It is a star that gets its energy from fusing hydrogen-1 into helium-4.
The main sequence - the region across the middle of the diagram.
Main sequence stars.
I assume the different points on the main sequence represent a kind of balance for the case of hydrogen-to-helium fusion.
In the HR-diagram, a diagram of color vs. luminosity, most stars are concentrated close to one curve, called the "main sequence". It turns out that stars on the main sequence are the stars that mainly get their energy by converting hydrogen into helium.
main-sequence stars
above the main-sequence stars
The lower right part of the main sequence in the Hertzsprung-Russell diagram contains the stars that took the longest to reach the main sequence. These stars are low mass and cool, so they undergo a longer contraction phase before they start fusing hydrogen in their cores and settle onto the main sequence.
Of course they are on the HR diagram. They are simply not on the main sequence.
The main sequence stars on the Hertzsprung-Russell diagram that are least massive are the red dwarfs. These stars have low masses compared to other main sequence stars like our sun. They are cooler and fainter, making them difficult to observe compared to more massive stars.
A main-sequence star is one that is along a curve where the majority of stars are located, when plotted in an H-R diagram. It is a star that gets its energy from fusing hydrogen-1 into helium-4.
The curve that currently contains most stars on the HR diagram is called the "main sequence". It consists of those stars that fuse hydrogen-1, converting it into helium-4.
The main sequence - the region across the middle of the diagram.
About 90 percent of the stars on the Hertzsprung-Russell diagram are main sequence stars, which are in the stable phase of hydrogen fusion in their cores. These stars span a range of spectral types and luminosities, representing the majority of stars in the universe.