Last Updated on July 31, 2021 by Neil Mackengie
“Countless as the stars at night.” This is the impression we pet of the sky when we look up at night and see the stars. But it may surprise you to know that onlyabout6,000stars can be seen without a telescope.
That does not mean a person can look up and count 6,000 stars. Because one-fourth of these 6,000 stars are too far south to visible in Western Europe. And of the stars that can be seen from any one place on earth, only one-half is visible at one time as the others are below the horizon.
What’s many of the stars near the horizon cannot be seen because of haze. So what do we end up with? If you started to count the stars that you could see, you would probably not be able to count many more than 1,000.
Photographs can be taken of the sky by a camera attached to a telescope. Many more stars can be counted on a photograph of a particular spot in the sky than the unaided eye can see there. And with time exposure, even more, stars will be added.
Finally, by using a very powerful telescope, it would be possible to photograph more than 1,000,000,000 stars!
Once a star is noticed in the sky it must be given a name or an identification number. Long ago, people in many lands—the Arabs, the Greeks, the Romans, and the Chinese—gave names to the brightest stars and to other stars that were in some way remarkable. More than 100 stars were given names.
And man has wanted to have a catalog of the stars that were known. The first known star catalog listed 1,025 stars and dated from about A.D. 137. A modern catalog of the stars lists more than 457,000 stars!
How Many Stars Can We See On A Clear Dark Night?
The number of stars that you can see on a clear (moonless) night in a dark area (far away from city lights) is about 2000. Basically, the darker the sky, the more stars you can see.
The first stars we see in the night sky are actually the brightest ones of all. They are called the “pointers,” and they appear to be the brightest because they are close to Earth. Beyond them lie other stars, which are much fainter. There are two types of stars: the “bright” ones and the “dimmest” ones. The dimmest ones are the ones we can see in the sky.
From a distance, stars may seem endless, but they are actually short-lived and subject to a range of different events over their lifetimes. For example, some stars are so massive that they burn out within 100 million years, while others may last for billions of years. Some stars even end up as a black hole or neutron star, which are super dense, yet theoretically still capable of producing gravitational waves.
The question: “Do stars die?” is an interesting one, and I’ve been pondering it for some time. After all, stars are big, hot balls of gas that can generate temperatures in excess of a million degrees. If there is life in the universe, it must exist in stars, so everything must eventually die.
What happens when a star dies, then is born again? The answer is surprisingly simple. When a star dies, the core of the star collapses inwards, into the core of the star, which is a dense region of the super-hot plasma. The super-hot plasma is like a ball of fire, and it’s surrounded by a thin layer of very thin gas atoms. The gas atoms are like balloons, and they have a diameter of only about 10 times the diameter of a hydrogen atom, about 0.1 nm. The temperature of the super-hot plasma is about 20,000 K, compared to a normal room temperature of about 300 K. If the star is a big helium core, the collapsing helium core would turn into a carbon core, which is about