Stars exist at a range of masses anywhere from perhaps a tenth of the mass of the Sun, through stars very much like the Sun, to stars perhaps even a hundred times the mass of the Sun—although these are quite rare. Astronomers tend to divide high-mass stars from low-mass stars at around about ten solar masses: ten times the mass of the Sun. So some of the main differences between high-mass stars and low-mass stars are that the high-mass stars are physically bigger but also, much more importantly, putting out a lot more energy. Theyʼre much more luminous, and so when we see them in a cluster of stars, for example, itʼs the high-mass stars which are really the brightest ones shining that really stand out. Thatʼs true actually also when we look at distant galaxies, most of the light we see from those galaxies is coming from the high-mass stars in those galaxies.