In the Sun's classification (G2V), what does the Roman numeral 'V' signify about its physical state?

Answer

It is currently fusing hydrogen in its core (main-sequence).

The luminosity class 'V' denotes a main-sequence star, meaning that the object is currently in the stable phase of its life cycle where it generates energy by fusing hydrogen into helium in its core.

In the Sun's classification (G2V), what does the Roman numeral 'V' signify about its physical state?
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