Neither, the sun is on the small side of the middle range of main sequence stars.
red
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.
The main sequence stars located at the bottom right of the Hertzsprung-Russell diagram are the least massive. These stars are low in temperature and luminosity, such as red dwarf stars, which have masses less than about 0.4 times that of the Sun.
Main sequence stars that are most massive are O-type stars, which can be more than 16 times the mass of the Sun. These stars are among the hottest and brightest in the main sequence and have relatively short lifespans compared to lower mass stars.
The most massive main sequence stars are typically blue in color, due to their high surface temperatures. These stars are known as O-type stars and can be tens of times more massive than the Sun.
Red
Yes, generally the hottest main sequence stars are also the most massive. This is because more massive stars have higher core temperatures and pressures, resulting in hotter surface temperatures. Therefore, there is a direct correlation between a star's mass and its surface temperature on the main sequence.
No. Main sequence stars vary greatly in both temperature and luminosity. The least massive stars, red dwarfs, can have temperatures as low as 2,300 Kelvin and luminosity as low as 0.015% that of the sun. The most massive stars, which are blue in color can have temperatures as high as 50,000 Kelvin and may be hundreds of thousands times more luminous than the sun.
O, because O stars are the hottest, so they use their energy faster than the lower stars.
If you refer to the diameter, a neutron is tiny - only 20-30 kilometers in diameter. In comparison, main sequence stars have a diameter of at least several hundred thousand kilometers.
The most massive main sequence stars are the brightest, (O main sequence star on Hertzsprung-Russel Diagram). Main sequence stars obey a mass-luminosity relation. On the H-R diagram the vertical axis is the brightness. So the stars along the top are the brightest (intrinsically).
No. Only massive stars can become supergiants.