Hello, I'm an expert in astronomy with a focus on stellar bodies and their characteristics. When discussing the smallest stars, we're often talking about the lower mass limit for what constitutes a star. This is typically defined by the mass at which a body of gas can initiate and sustain nuclear fusion of hydrogen into helium, which is the process that powers most stars.

The smallest known stars are red dwarfs, which are main-sequence stars with a mass around 0.075 to 0.5 times the mass of our Sun. However, even below this range, there are objects known as brown dwarfs, which are not massive enough to sustain hydrogen fusion but can still undergo fusion of deuterium or helium at least for a time.

The smallest known main-sequence star that is still considered a true star is EBLM J0555-57Ab, discovered in 2017. It has a mass just slightly larger than that of Jupiter, the largest planet in our solar system.

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The smallest stars around are the tiny red dwarfs. These are stars with 50% the mass of the Sun and smaller. In fact, the least massive red dwarf has 7.5% the mass of the Sun. Even at this smallest size, a star has the temperature and pressures in its core so that nuclear fusion reactions can take place.read more >>