Here I will tell you, what is this mysterious dark matter that accounts for the majority of the mass of the universe. You will also know the primary evidences that made us to believe in the presence of dark matter in our universe.
What is Dark Matter
You will be surprised to know that, The total mass and energy of the universe contains only 5% ordinary matter and energy. The remaining 95 percent of the mass and energy is composed of mysterious things. This 95% contains 27% of dark matter and 68% of dark energy. Here we will learn some interesting facts about the dark matter. The dark matter is actually a hypothetical matter that cannot be detected by its emitted radiation, but we can feel its presence because of its gravitational effects on the visible matter.
Why is Dark Matter called Dark?
Dark matter is called as dark because it is extremely difficult to detect using usual astronomical equipments. The reason behind this is; Dark matter does not appear to interact with the observable electromagnetic radiations such as light and hence it is not visible to the entire electromagnetic spectrum. As I just mentioned, that majority of the total mass of our universe, i.e. 95%, is made up of dark matter and dark energy. so we cannot neglect its presence. It is thought that, majority of dark matter is possibly being composed of some undiscovered subatomic particles.
Dark matter is present everywhere and had a strong influence on the structure and evolution of our universe. Now I will tell you some primary evidences, that helped us in believing that dark matter is present in our universe.
Proof of Dark Matter
In 1884, a mathematical physicist and engineer lord Kelvin performed some experiments. Based on this, he estimated that the mass of the Galaxy that he determined is different from the mass of visible stars. So he concluded that "many of our stars perhaps a great majority of them, maybe dark bodies." It Has been Shown by the calculations that many galaxies would fly apart instead of rotating, or would not have formed or move as they do, if they did not contain a large amount of matter that cannot be seen. Some Other evidences for the presence of dark matter in the universe are : #Gravitational Lensing #Formation and evolution of galaxies #Mass Location during galactic collisions #From observations of current structure of the universe #From the motion of galaxies within Galaxy clusters #From the cosmic microwave background So based on all these evidences, we can say that dark matter is not just a hypothetical concept. It really Exists!
What is QUASAR (Quasi Stellar Radio Source) and Why it is so Awesome?
Quasars are the brightest and most distant objects in the known universe. Quasar contains a supermassive black hole at its center having mass ranging from millions to billions of times the mass of the Sun. This supermassive Black hole is surrounded by an accretion disk. This accretion disk is a circular disc like structure which is made up of different types of gases and matter that spins around the black hole at an extremely high speed. This giant disk feeds the hungry supermassive black hole. As matter starts falling into the black hole from the accretion disk, the friction between the fast spinning matter slowly heats up that causes tremendous amount of energy emission from it. As the accretion disc rotates, the charged particles are shot upward. These charged particles form a tight column because of the twisted magnetic field lines which is known as the quasar jets, cosmic Jets or astrophysical jets. The charged particles that are present in the quasar Jets travel at nearly the speed of light and can shoot out to very long distances. This makes them visible from Earth, although they are present at a distance of billions of light years away from Earth.
Keep it in mind that, the quasar jet does not originate from the center of the black hole but is ejected from the spinning disc of gas and matter. Finally this extremely hot and fast spinning accretion disk in eaten up by the supermassive giant black hole. You will find it hard to believe that The largest quasars can eat up mass equivalent to 600 earths every single day!. If we talk in terms of mass of the Sun, it can feed a mass equal to the mass of 1000 suns every year. But When the quasar eats up the whole matter present in the accretion disk, it eventually dies, as there is nothing left for it to feed on. "Quasars" is actually a short name for Quasi Steller Radio Sources. Quasars actually belong to a family of astronomical objects known as the Active Galactic Nuclei (AGN), The Quasars are the most distant and most energetic objects of all the objects in the Active Galactic Nuclei. The brightness of most powerful Quasars may be upto thousands of times Greater than a Galaxy containing hundreds of billions of stars such as the Milky Way. Quasars are not just the brightest objects in the universe, they are also the most distant objects ever found. Generally quasars are found millions or billions of light years away. The most distant quasar discovered is the ULAS J1120+0641 that is present at a distance of 29 billion light years away from us. Even the closest Quasar known as IC 2497 is 730 million light years away from earth. The first quasar discovered by the scientists was 3C 273 which was found in the year 1950. As of date nearly 200 thousand quasars have been discovered. As we know that quasars are billions of light years away from earth so they are surely the most ancient objects known to us. This helps us in understanding the mysteries of the early universe. According to scientists our galaxy Milky Way once hosted a quasar but now it's not alive. But nearly after 5 billion years from now, the milky way galaxy will collide with its neighbouring Andromeda Galaxy, at that time the Milky way may have a Quasar. Researchers have found that quasars are drifting away from us at an unbelievably high speed of 150 thousand kilometers per sec. Some quasars have been seen moving even at 93% of the speed of light. So friends this was all about the brightest thing in the universe, the Quasars!!!
Here in this interesting article you will know 20 Unbelievable and unknown facts about our home Galaxy, the Milky Way. Go through the post till the end as these Milky way facts are sure to blow your mind !!! You can also Watch the complete Video about these 20 Amazing Facts about the Milky Way Galaxy below-
20 Amazing Facts about the Milky Way Galaxy Video
Milky Way Galaxy Fact 1
The Galaxy where we live is known as the Milky Way. The milky way is a spiral shaped Galaxy containing upto 400 billion stars that also includes our own star the Sun. So the Sun is present in the Milky way galaxy along with its member planets containing our home planet Earth.
Milky Way Galaxy Fact 2
Our solar system is located in one of the spiral arms of the Milky Way. We are present at a huge distance of 26,000 light years from the centre of our Galaxy. Here let me tell you that one light year is equal to nearly 9.46 trillion kilometres.
Milky Way Galaxy Fact 3
In March 2019, astronomers reported that the mass of the Milky Way galaxy is equivalent to 1.5 trillion solar masses, which was over twice as much as was calculated in previous studies. It suggests that nearly 90% of the mass of the Milky way Galaxy is the mysterious Dark Matter.
Milky Way Galaxy Fact 4
Let's now talk about the size of our Galaxy, The diameter of Milky way is more than 150 thousand light years. It means, Our galaxy milky way is so big that even if we could travel with the speed of light, which is the maximum speed possible theoretically i.e. 300k km per sec., it would take 150k years to travel from one end of the milky way to the other.
Milky Way Galaxy Fact 5
When we see the milky way at night with our naked eyes, we see only about 0.0000025% of the galaxy's hundreds of billions of stars.
Milky Way Galaxy Fact 6
Our Milky Way galaxy contains a supermassive black hole at its centre having a huge mass equivalent to 4 million Suns. This giant black hole is known as Sagittarius A*. Here you should not think that sagittarius A* is the only black hole that our galaxy contains. This Is the biggest black hole present in the Milky way. Actually our galaxy may contain nearly 100 million black holes.
Milky Way Galaxy Fact 7
Our milky way is a barred spiral galaxy. Barred means, central part of the milky way is bar shaped rather than an ordinary spiral galaxy.
Milky Way Galaxy Fact 8
The stars that are present in the arms of the spiral galaxy are bigger and brighter. Not only this, these stars also die out more quickly.
Milky Way Galaxy Fact 9
The oldest star present in the Milky Way was formed shortly after the big bang. Astronomers have estimated that this star was formed at least 13.6 billion years ago. Having so old star means that the Milky Way came into existence just after the Big Bang. So our Galaxy is one of the oldest Galaxies present in the universe.
Milky Way Galaxy Fact 10
The Milky Way has grown in size by merging with its neighbouring galaxies with time. Currently it is sucking up material from the magellanic clouds and snatching Stars from a very small Galaxy known as the sagittarius dwarf spheroidal.
Milky Way Galaxy Fact 11
You will find it unbelievably surprising, that the milky way is moving through space at a speed of nearly 552 kilometres per second. This speed is measured with respect to the cosmic microwave background radiation.
Milky Way Galaxy Fact 12
According to astronomers, in the next 5 billion years, our Milky Way galaxy will collide with its neighbouring Andromeda Galaxy. The two Galaxies are moving towards each other at very high speed of 120 kilometres per second. This collision may last for about 5.5 billion years. When the collision Is over, the Milky Way and Andromeda galaxies will no longer be two spiral galaxies. They will form a single and bigger elliptical galaxy.
Milky Way Galaxy Fact 13
Do You know that there are billions of galaxies smaller and larger than the milky way in the universe? The Milky Way galaxy is a huge group of stars, dust, gas and other material, which is held together in space because of their mutual gravitational force of attraction.
Milky Way Galaxy Fact 14
Researches show that the Milky Way has a halo of dark matter. The halo makes up over 90% of its total mass. So even with the help of telescopes what we can see, is only 10% of the mass of the Milky Way.
Milky Way Galaxy Fact 15
The stars present near the centre of the Milky Way are the oldest and most massive stars while the spiral arms of the Galaxy mostly contain newborn stars.
Milky Way Galaxy Fact 16
Even though there are 400 billion stars in The Milky Way galaxy, still the nearest star, the Proxima Centauri is present at a distance of more than 4 light years from us. Keep it in mind, that our Sun is actually the nearest star to the earth, the proxima Centauri is nearest after the Sun.
Milky Way Galaxy Fact 17
All the galaxies are categorised into three main groups on the basis of their shapes. These types are- Spiral galaxies like our own Galaxy the Milky Way, Elliptical galaxies and Irregular galaxies.
Milky Way Galaxy Fact 18
As we know that our home planet earth is revolving around the sun, but do you know that our whole solar system along with its all the member planets is also orbiting the centre of the Milky Way Galaxy!!! The solar system is revolving around the Centre of the milky way really fast, at a speed of about 220 kilometres per second. But even at this high speed it takes it about 230 million years to complete just one revolution around the centre of the Milky Way. Therefore this period of 230 million years is called as one Galactic year.
Milky Way Galaxy Fact 19
The Milky Way is not just travelling through the space at extremely high speed, it also has rotational motion. It's spinning at 270 kilometres per second and takes nearly 200 million years just to complete one rotation. With this fact only, you can imagine the size of the Milky Way.
Milky Way Galaxy Fact 20
The milky way is popular by different names in different countries and civilizations, like in China, it is known as "The silver river". Romans called our galaxy "The Milky Road". The Greeks called it the "Milky Circle". It's interesting to note that, the word "Galaxy" itself means "Milk" in Greek. In Sanskrit the Milky way is called the "Akash Ganga" or Ganges of the heavens". So these were some incredible Top 20 Facts about our beautiful, Old and Huge Galaxy, The Milky Way. Go to HOME PAGE Universe Origin Theories, Beginning, Evolution and Future of the Universe (BIG BANG Theory, Steady State Theory and Pulsating Theory)
What will you know here about UY Scuti - The Largest Star in the Universe
UY Scuti is the largest known Star in the universe. It is also known as BD 12 5055. Here we will compare the UY scuti with the Sun i.e. UY Scuti vs Sun. Various properties of UY Scuti star will be discussed in this post like its Size, Mass, Volume, Radius. You will surely enjoy the unbelievable facts about the largest Star in the Universe.
How Big is UY Scuti (UY Scuti Vs Sun)
Our Sun may appear to be the largest star to us as it is closest from the earth. But you should know that the sun is a quite average sized star in the universe in comparison to other trillions of stars in the universe. But in this post, we are going to talk about the largest known star in the universe. The size of our Sun is negligible if we compare it to the size of this star.
The name of this Hypergiant star is UY Scuti also known as BD-12 5055. The volume of UY scuti is 4.98 billion times the volume of the Sun. It means this Hypergiant star can fit nearly 3.69 billion Suns inside it. Its radius is 1700 times larger than the sun. You will be amazed to know that the size of UY scuti is so big that the distance between the two ends of the star is equal to 8 times the distance between the Earth and the Sun. Even if we travel at the highest possible speed, that is, the speed of light, it would take about 7 hours to travel along the UY Scuti's great circle. For comparison, let me tell you that, it would take only 14.5 seconds to circle the sun. Assuming its maximum possible size it can fit all the planets upto Saturn of our solar system. So now you can imagine how huge the UY Scuti is.
How far is UY Scuti from Earth
UY Scuti is present in the constellation Scutum. This is a pulsating variable star. It means, the brightness of the star fluctuates as seen from Earth. It grows brighter and dimmer over a 740-day period. UY Scuti star is present near the centre of our Milky Way galaxy at a very large distance of 9500 light years from the earth.
Mass of UY Scuti
Although the UY Scuti is the largest known star but it does not have the highest mass. Its mass is only slightly more than 30 times the mass of our Sun. So which is the most massive star scientists have ever found? Actually R136a1 is the most massive known star in the universe. So here you should remember that largest known star and most massive known star are not the same.
How Old is UY Scuti (Age of UY Scuti)
The age of UY Scuti star is not certain. According to scientists, it could be as young as few million years or as old as a few billion. So friends these were some amazing facts about the largest known star in the universe. As there is no end of this universe, scientists may find even bigger stars in future.
