Nuclear fusion requires extremely high temperature and pressure. Atomic nuclei are all positively charged, and therefore repel each other. It takes a lot of energy to make them get close enough to react. As a result, fusion does not take place throughout the body of a star, it takes place only in the center of the star. So most of the mass of a star is not undergoing fusion, at any given time. Therefore, stars do not consume their fuel rapidly, and they last a long time, billions of years.
yes
The HR diagram does not reference stars on their way to the main sequence, only during or after.
The temperature of main sequence stars can vary quite a bit.
Beacuse they are dimmer, but they're also bigger than the main sequence stars.
above the main-sequence stars
There are billions of stars that are not on the main sequence.
Of the stars you can see from Earth, 90% are in the main sequence.
The smallest stars in the main sequence are the stars with cooler surface temperatures.
"main sequence" is the tern.
Most of the stars in the universe are found on the main sequence. Stars fall off the main sequence when they begin to die.
main sequence stars , our sun is also a main sequence star
About 90% of the observed stars are on the main sequence. See related question
main sequence stars , our sun is also a main sequence star
Main sequence stars include the hottest stars as well as the coolest ones.
No. They have the lowest temperatures on the main sequence. The hottest main sequence stars are blue.
Main sequence stars are found in all galaxies.
Main sequence stars.