4 mind-blowing facts about the stars
When people think of the universe, they think of stars. Stars are mostly visible matter in the Universe, and despite the fact that they are all outside our Sun, which is unthinkable far from us, we can see thousands of them with the naked eye, but only at night.
1) In fact, there is an immeasurable number of stars in the visible part of the universe.
Did you know that when you are at night in the countryside and the moon does not interfere with admiring the sky, you can see thousands of stars?
In these optimal conditions, at the most, what you can see is about 2500 stars. This is about 1 / 100,000,000th part of the total number of stars only in our own galaxy.
Speaking of this, let's also look at our magnificent Milky Way. To help you understand how crazy he is, here are some facts:
- The diameter of the Milky Way is 100,000 light years. A light year is the distance that light travels in one year. Considering that light travels around the earth seven times around the Earth in one second, a light year is an inconceivably long distance.Our fastest spacecraft will take 18,000 years to fly one light year. And speaking of the Milky Way, we are talking about 100,000 light years!
“It also means that if you use a telescope to see a star at the far end of the Galaxy, you actually see what this star looked like 100,000 years ago, because the light that shone with the star only now comes to us.”
Similarly, if at this moment, someone on the other side of the galaxy decided to view the Earth with a telescope, he would see a bunch of early people and Neanderthals who lead erratic lives and beat each other with clubs like fools.
“You might think that if you take a closer look at the image of the Milky Way, then one of all the small points could be our Sun.” In fact, if you enlarge the above photo even to the size of our Earth, you still have to use a microscope to see our Sun, the size of a small dot. If the Milky Way is the size of Earth, then the size of the Sun will be approximately 1/50 of a millimeter in diameter.
He is huge. And in general, the Milky Way contains from 100 to 400 billion stars.
And this is only one galaxy.
In 1995, scientists chose a small portion of the night sky, which seemed unusually starless in appearance. To the naked eye, and even when viewed with an ordinary telescope, this region looked empty and black. This piece of space was very tiny, it covered the same sky that a tennis ball can cover if it is located 100 meters above you (the image on the right shows the size of that area, compared to the size of the moon in the night sky).
Scientists used the Hubble telescope and explored the empty region for 10 days to find what was hidden deep in the dark. And they got the result:
To be clear, nothing in this photo is a star. Every thing you see, even the smallest point, is a whole galaxy.
There are about 10,000 of them in this image, and each of them contains about 100 billion stars. And again, it all fits in a small area of the night sky, the size of a pinhead.
Scientists, based on data obtained from this photo, suggested that the part of the Universe that we observe contains more than 100 billion galaxies, which means that the total number of stars in the observed Universe is in the range of 10 to 22 degrees to 10 to 24 degrees, about 100 sextillion stars.
To present this in perspective, scientists from the University of Hawaii spent a lot of time calculating and calculated that the number of grains of sand in the world is 7.5 trillion, or 7.5 x 10 in 18 degrees.
This means that for every grain of sand on Earth there are about 10,000 stars in the universe.
2) The stars are not located close to each other.
If we consider the binary star systems, most of the stars are located there, at great distances from each other in any direction, and therefore we can say that they are all alone.
Our Sun is no exception - the star closest to us, Proxima Centauri, is at a distance of 4.24 light years, which equals 70,000 years for our fastest spacecraft.
So, if the Sun were a 4-centimeter ping-pong ball located in New York, the star next to us, another ping-pong ball, would have to be 1153 kilometers away, that is, in Atlanta.
3) Some stars are incredibly huge.
The largest stars are called red hypergiants. One of them is simply absurdly large, it is called VY of the Big Dog. If you fold 1420 of our Suns on each other, then you will get the diameter VY of the Big Dog. Here is how it looks next to the Sun:
Or, if you go back to the fact that the Sun is the size of a ping-pong ball, then you will need a 16-story building to represent the height of the VY of the Big Dog. An ordinary plane in order to fly around this star will take about 1100 years, and if the VY of the Big Dog were in the center of our Solar system instead of our Sun, it would swallow everything up to the orbit of Saturn.
Another red hypergiant is almost as big as the VY of the Big Dog called Betelgeuse. You can see it on any starry night in the upper left corner of the Orion constellation.
4) Some stars are incredibly tiny and dense.
When a big star dies from an explosion and turns into a supernova, a gravitational collapse and the formation of a neutron star can happen.
Normal matter consists of atoms, and atoms consist of almost completely empty space. The only thing that gives the atom its mass is the tiny nucleus in its middle. So that you can clearly imagine this, suppose that the atom is a large sphere with a diameter of 1 km - this sphere is so large that you could lay down two Empire State buildings inside it without hitting their ceiling. If this sphere is an atom, then the nucleus will be just one pea, floating freely in its middle, and the mass of the atom will be the same as the mass of this pea.
During the gravitational collapse and the creation of a neutron star, what happens is that the atoms start to nestle very tightly against each other, because the empty space of each of them starts to decrease and all the peas in the middle of each atom suddenly bump against each other. So now imagine that a sphere with a diameter of 1 km is full of peas. Therefore, now 1 km of space, instead of having a mass of 1 pea, has a mass of about 1,000,000,000,000,000 peas.
This is what happens when a neutron star is formed - there is no empty space in it, only neutrons, which are densely located atomic nuclei (and it is a quadrillion times denser than normal stars).
The result of this process is a tiny star with a diameter of only about 24 km, but a mass of as many as three suns or a million such planets as the Earth. The size of the neutron star is shown below (imagine that it holds 1,000,000 planets of the Earth):
Some amazing facts about the neutron star:
- One of its teaspoons has a mass equal to 900 Pyramids of Cheops.
- The density of a neutron star is the same as that of a compressed Boeing 747 in a small grain of sand.
- There are some stars that spin at a speed of 642 times per second. This means that the point at the "equator" of such a star moves every second to a greater distance than the circumference of the Earth.
- Neutron stars are hot. The temperature inside a neutron star ranges from 10 to 11 degrees to 10 to 12 degrees of degrees Kelvin — this is more than 1000 times hotter than the core of the sun.