Where is the Sun plotted on the Hertzprung-Russell diagram?

The Sun is plotted on the main sequence of the Hertzsprung–Russell diagram.

The H–R diagram compares stars by luminosity or absolute magnitude and surface temperature or spectral class. The main sequence is the prominent diagonal band running from hot, bright stars at the upper left to cool, faint stars at the lower right. The Sun sits near the middle of this band because it is a medium-temperature, medium-luminosity star.

A star belongs to the main sequence while it is fusing hydrogen into helium in its core. The Sun has been in this phase for about 4.6 billion years and is expected to remain there for roughly another 5 billion years. Its spectral classification is G2V: “G2” describes its surface temperature and “V” identifies a main-sequence, or dwarf, star.

A common mix-up is placing the Sun among the red giants because it will eventually become one. That is a future evolutionary stage, not its current position. After its core hydrogen is depleted, the Sun will leave the main sequence, expand into a red giant, and ultimately end as a white dwarf.