Beyond the Night Sky: A Dive into the World of Stars

Let’s take a journey through the cosmos and explore the captivating world of stars. These celestial bodies are more than just distant points of luminosity, they are fiery spheres of wonder that illuminate our night sky.

Stars are incredibly complex things that release heat and light through an intricate process called nuclear fusion. Nuclear fusion is when atomic nuclei are put under so much heat and pressure that they are forced to merge together and form heavier elements, turning hydrogen into helium. And boy, does this process release a whole bunch of energy in the form of light and heat!

(Department Of Energy)

As the fusion process continues, the energy produced in the core begins to radiate outward. This energy first passes through the radiative zone, where it is carried by photons, before reaching the convective zone. In the convective zone, hot gas rises to the surface while cooler gas sinks back down, creating convection currents that help to transport the energy outward. Finally, we get to the star’s outermost layer, the photosphere, which is the part of the star that we can actually see.

(Astronomy 122 - The Sun)

Fun fact: the temperature and pressure in this layer determines the star’s color! For example, hot stars are all flashy blue, while the cooler ones have a cozy red glow.

Now that we know how they work, how are they born? The incredible journey of stars begins in what we describe as a stellar nursery, This is where thick, fluffy clouds of gas and dust come together and collapse in on themselves, creating an intriguing entity: the protostar.

(Discover Magazine)

A protostar can be considered as a “baby” star. Once it hits the right temperature and density, it becomes a main sequence star. It starts burning massive amounts of hydrogen, turning it into helium in its core.

Like all things, stars unfortunately do not last forever, as once they start running low on hydrogen fuel, they decide to go out with a bang! The main sequence star will begin puffing up and turn into a red giant star. Once the star knows its time is approaching, it sheds its outer layers in a dazzling process known as a planetary nebula. What’s left behind is a hot, little core all on its own, called a white dwarf. That’s one way to go, but for supermassive stars, it’s a different story. When they run out of fuel, their core collapses, causing a massive explosion called a supernova. After a supernova, the remaining material from the star can either become a neutron star or a black hole.

(The Schools' Observatory)

From birth to demise, stars paint a captivating story of cosmic life cycles, revealing the fascinating processes shaping our celestial realm.