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What causes the light we see in a star?

What causes the light we see in a star?

Stars shine because they are extremely hot (which is why fire gives off light — because it is hot). The source of their energy is nuclear reactions going on deep inside the stars. In most stars, like our sun, hydrogen is being converted into helium, a process which gives off energy that heats the star.

How many years does it take for the light of a star to reach Earth?

Other Galaxies

Object Time for the Light to Reach Us
Alpha Centauri (nearest star system) 4.3 years
Sirius (brightest star in our sky) 9 years
Betelgeuse (bright star) 430 years
Orion Nebula 1500 years

Is it possible for you to see light from a star that no longer exists?

Therefore, when you look at a star, you are actually seeing what it looked like years ago. It is entirely possible that some of the stars you see tonight do not actually exist anymore. Therefore, even if a star that we see in the sky does not really exist anymore, this fact means nothing to us at the current moment.

How long does a star live for?

about 10 billion years
Generally, the more massive the star, the faster it burns up its fuel supply, and the shorter its life. The most massive stars can burn out and explode in a supernova after only a few million years of fusion. A star with a mass like the Sun, on the other hand, can continue fusing hydrogen for about 10 billion years.

What star color is the hottest?

Blue stars
White stars are hotter than red and yellow. Blue stars are the hottest stars of all. Stars are not really star-shaped. They are round like our sun.

Can light travel forever?

If there were no objects to absorb light, it would keep traveling forever. Light is made up of particles called photons that travel like waves. Unless they interact with other particles (objects), there is nothing to stop them. If it is infinite, the light would travel forever.

When you see a star How old is it?

So, at most, you are seeing stars as they appeared 4,000 years ago. All of these stars will die at some point, and astronomers have estimated that the death rate for visible stars in our Milky Way is around one star every 10,000 years.

Are we made of stardust?

Planetary scientist and stardust expert Dr Ashley King explains. ‘It is totally 100% true: nearly all the elements in the human body were made in a star and many have come through several supernovas.

What color of star lives the longest?

red dwarfs
The stars with the longest lifetimes are red dwarfs; some may be nearly as old as the universe itself.

Which star has the shortest life expectancy?

Life span: The most massive stars have the shortest lives. Stars that are 25 to 50 times that of the Sun live for only a few million years. They die so quickly because they burn massive amounts of nuclear fuel.

Which color star is the coldest?

Red stars
You can tell the temperature of the star. Red stars are the coolest. Yellow stars are hotter than red stars. White stars are hotter than red and yellow.

What is the hottest natural thing in the universe?

The dead star at the center of the Red Spider Nebula has a surface temperature of 250,000 degrees F, which is 25 times the temperature of the Sun’s surface. This white dwarf may, indeed, be the hottest object in the universe.

How can light have traveled millions of years?

One of the most common questions thrown at creationists is to ask them to explain how light could have traveled millions of years across the universe, if the universe is only 6,000 years old. Such a question actually contains its own misunderstanding of the facts.

How is a light year related to time?

A light year is a unit of distance, not a unit of time. It obviously has a relationship to time, in this sense: Light is observed to travel at a speed of approximately 186,000 miles per second, through a vacuum. Therefore, in a year, we can calculate that the light should have traveled:

What happens to stars in thousands of years?

But thousands of years is but an eyeblink in the lifetime of a galaxy, and the notion that the stars don’t change positions is false. The stars do move, largely in bulk as they rotate around the center of the Milky Way, but sometimes they zip off in random directions dictated by the conditions of their formation or past interactions.

What will the sky look like in 5 million years?

Now you don’t have to — Gaia has the answer. In five million years, the sky will look a little different. The constellations will be unrecognizable, and many of the stars we can see today will have moved significantly. Have you ever wondered what it would be like to stare up at the sky millions of years from today?