Yes, a star can have less than half the mass of the Sun. In fact, there are many stars that are much smaller and less massive than our Sun.

Here's why:

* Brown Dwarfs: These objects are often called "failed stars" because they lack the mass to sustain hydrogen fusion in their core, which is the process that powers stars. Brown dwarfs have masses between roughly 13 to 80 times that of Jupiter, which is significantly less than half the Sun's mass.

* Red Dwarf Stars: These are the most common type of star in the Milky Way galaxy. They are much smaller and cooler than our Sun, with masses ranging from about 0.08 to 0.5 times that of the Sun. While they do undergo nuclear fusion, they do it at a much slower rate than larger stars, giving them extremely long lifespans.

So, while the Sun is a relatively average-sized star, there are many stars out there that are much smaller and less massive.