Sure, there are some color differences when you look up at the night sky. But aren’t they all basically the same, big balls of gas burning billions of light years away? No, not exactly. Stars, in fact, are as diverse as anything else in our Universe, falling into one of many different classifications based on their distinguishing characteristics like color of stars, temperature of stars or brightness. There are numerous types of stars, ranging from tiny brown dwarfs to red and blue supergiants. There are even more unusual types of stars, such as neutron stars and Wolf-Rayet stars. And as we continue to explore the Universe, we learn new things about stars that force us to reconsider how we think of them. Let’s take a look at all the different types of stars there are.
Stars are the most well-known astronomical objects, and they are the fundamental building blocks of galaxies. The age, distribution, and composition of stars in a galaxy reveal information about the galaxy’s history, dynamics, and evolution. Furthermore, stars are responsible for the production and distribution of heavy elements such as carbon, nitrogen, and oxygen, and their properties are inextricably linked to the properties of the planetary systems that may form around them. As a result, the study of star birth, life, and death is central to the field of astronomy.
What are stars made of?
Stars are massive celestial bodies composed primarily of hydrogen and helium that generate light and heat from the churning nuclear forges inside their cores. Aside from our sun, the light dots we see in the sky are all light-years away. They are the building blocks of galaxies, of which the universe contains billions. It is impossible to know how many stars exist, but astronomers estimate that there are approximately 300 billion in our Milky Way galaxy alone. Basically, stars are big exploding balls of gas, mostly hydrogen and helium.
Our nearest star, the Sun, is so hot that a massive amount of hydrogen is constantly undergoing a star-wide nuclear reaction, similar to that of a hydrogen bomb. Even though it is constantly exploding in a nuclear reaction, the Sun and other stars are so massive and contain so much matter that it will take billions of years for the explosion to consume all of the star’s “fuel.” The massive reactions occurring in stars are constantly releasing energy into the universe, which is why we can see and locate those using radio telescopes such as those in the Deep Space Network (DSN). Stars, including the Sun, also emit a solar wind and produce solar flares on occasion.
Scientists think that the core of the Sun is a 15 million degree Celsius plasma, a soup of electrons and protons that are stripped from hydrogen atoms. This “soup,” known as plasma, accounts for 90 percent of the mass of sun. Thousands of protons collide with other protons in the Sun’s core every second, producing helium nuclei in a nuclear fusion reaction that releases energy. Radiation is a process by which energy moves outward from the core. Closer to the surface, energy escapes through a process known as convection, in which hot gases rise, cool, and sink. As these masses of gas move, they push against one another, resulting in “Sun-quakes.” These cause the Sun’s material to vibrate. These Sun-quakes aid scientists in determining the Sun’s internal structure and the processes that occur at various locations beneath the surface of Sun.
Do stars have gravity?
A star is a gas-filled sphere held together by its own gravity. Our Sun is the closest star to Earth, so astronomers have a nearby example to study in depth. We can apply what we’ve learned about the Sun to other stars. The life of a star is a constant struggle against the force of gravity.
Do stars move?
The stars are not fixed, but rather move constantly. When you take into account the daily arcing motion of the stars across the sky caused by the earth’s rotation, you get a pattern of stars that never seems to change. The stars appear to be so fixed that ancient sky-watchers mentally connected the stars into figures (constellations) that we can still see today. In reality, however, the stars are constantly moving. They’re just so far away that the naked eye can’t see anything.
How stars shine?
Stars shine because they are extremely hot (just as fire emits light because it is hot) i.e. the temperature of star is too high. Their energy is derived from nuclear reactions occurring deep within the stars. In most stars, including our sun, hydrogen is converted into helium, releasing energy that heats the star.
Types of stars
The primary characteristics that we use to distinguish types of stars are brightness and color. It’s difficult to judge brightness unless we know how far away something is. Color is easier to see, and you can use telescopes, binoculars, or even a cardboard tube to block out stray light and help you focus on the star itself. There are numerous online tools that can help you determine where to look for any specific star from your location and at the time you are awake.
A protostar is a collection of gas that collapsed from a massive molecular cloud before forming into a star. This phase of stellar evolution lasts approximately 100,000 years. During this time, just as the gas collection collapsed to form the protostar, the protostar collapses due to an increase in gravity and pressure. This process produces a pre-main-sequence star, which later transforms into a main-sequence star as hydrogen fusion begins.
T Tauri Stars
Types of stars: T Tauri stars, also known as pre-main-sequence stars, exist after protostars but before main-sequence stars. These stars represent youth and are named after a young star that formed in the Taurus star-forming region. The gravitational pressure that holds the star together is also the source of all its energy at this point in its evolution. They do not have enough pressure or a high enough temperature in their cores to initiate nuclear fusion at this point. They are, however, about the same temperature as main-sequence stars, albeit brighter due to their larger size. A star will spend approximately 100 million years in its T Tauri stage before evolving to its next form.
Main Sequence Star
Main sequence stars make up the vast majority of stars in our galaxy and even the Universe. Our Sun, as well as our nearest neighbors Sirius and Alpha Centauri A, are main sequence stars. Main sequence stars vary in size, mass, and brightness, but they all do the same thing: in their cores, they convert hydrogen into helium, releasing a tremendous amount of energy. A main sequence star is in a state of hydrostatic equilibrium. Gravity pulls the star inward, while light pressure from the star’s fusion reactions pushes it outward. The inward and outward forces balance each other, and the star retains its spherical shape. The size of stars in the main sequence is determined by their mass, which defines the amount of gravity pulling them inward.
Red Giant Star
Types of stars: When a star’s supply of hydrogen in its core is depleted, fusion ceases, and the star no longer generates an outward pressure to counteract the inward pressure pulling it together. A shell of hydrogen surrounding the core ignites, extending the star’s life but causing it to grow dramatically in size. The ageing star has evolved into a red giant, which can be 100 times larger than it was during its main sequence phase. When this hydrogen fuel is depleted, fusion reactions can consume additional shells of helium and even heavier elements. A star’s red giant phase lasts only a few hundred million years before it runs out of fuel and becomes a white dwarf.
White Dwarf Stars
When a star consumes all of the layers of helium in its core and runs out of other elements to use as fuel, it becomes a white dwarf. When the fusion reaction’s outward light pressure ceases, the star collapses inward due to its own gravity. Despite the fact that the fusion reactions have ceased, the star continues to shine due to its immense heat. It will take hundreds of billions of years for the white dwarfs to completely cool down, which means we still don’t know what will happen to the stars once this stage is over.
Red Dwarf Stars
Types of stars: These are members of the main-sequence star group. Red dwarf stars are the most common type of stars in the universe. These stars have such a low mass that they are much cooler than stars like our Sun. They can keep the hydrogen fuel in their core mixing. As a result, they can save fuel for a much longer period of time. As a result, astronomers predict that red dwarfs will burn for up to 10 trillion years.
When a star dies, it does not form a white dwarf if its mass is between 1.35 and 2.1 times that of the Sun. Instead, the star explodes in a supernova, and the remaining core becomes a neutron star. A neutron star, as the name implies, is a rare type of star made entirely of neutrons. This is due to the neutron star’s intense gravity, which crushes protons and electrons together to form neutrons. If the stars are even more massive, after the supernova, they will become black holes rather than neutron stars.
Yes, you guessed it: these are the universe’s largest stars. Supergiants are massive, dozens of times the mass of the Sun. These stars die out after only a few million years because they consume their hydrogen fuel at such a rapid rate. When a supergiant star dies, it produces a supernova explosion and disintegrates completely.