Build Your Own Star
Stars come in many sizes and colours, from tiny cool red dwarfs to enormous blue-hot giants. A star’s entire life is shaped by just three things: how massive it is, how hot it is, and how old it is. We measure mass in solar masses (M☉), where 1 M☉ = the mass of our Sun. Small stars live for trillions of years; very massive stars burn bright and die quickly.
Most stars spend their long, stable lives on the main sequence, where they fuse hydrogen into helium. When they run out of fuel, their fates depend on their birth mass: Sun-like stars become red giants and end as white dwarfs (never heavier than about 1.4 M☉, the Chandrasekhar limit), while the most massive stars explode as supernovae and collapse into neutron stars or black holes.
Astronomers use the Hertzsprung–Russell (HR) diagram to sort stars by brightness and temperature. Below gives you a quick overview of star types and how different masses evolve. Then you can build your own star and see where it fits, or whether physics says it’s impossible!
Stellar Types at a Glance:
From hottest to coolest main-sequence stars:
O ✦ B ✦ A ✦ F ✦ G ✦ K ✦ M
O stars are massive and blue-hot. M stars are tiny, cool, and red.
There are 17 star types in this lab! Think you can build them all?
Try to create: Brown dwarf, Red dwarf (M), Orange dwarf (K), Sun-like G star, F star, A star, B star, O star, Red giant, Blue giant, Supergiant, Hypergiant, Wolf–Rayet, White dwarf, Neutron star, Pulsar, and a Black hole.