What can you infer about the total number of stars in the universe?

“Scientists recently determined that the number of visible stars in the universe is 70 sextillion.” Based on this information, what can you infer about the total number of stars in the universe? There may be fewer than 70 sextillion stars in the universe because scientists were not counting stars one by one.

Why is there so much more matter than antimatter?

So why is there far more matter than antimatter in the universe? The Big Bang should have created equal amounts of matter and antimatter in the early universe. Matter and antimatter particles are always produced as a pair and, if they come in contact, annihilate one another, leaving behind pure energy.

How do we know there aren’t antimatter galaxies?

“When matter and antimatter meet, they annihilate each other and the mass is converted into energy–specifically, into gamma-rays. “We do not see any steady stream of gamma-rays coming from any source in the sky. Therefore, astronomers conclude that there are not occasional ‘rogue’ galaxies made of antimatter.

What are Antistars?

Antistar, an orientation diametrically opposite the direction of a star sometimes used when describing the direction of a comet’s tail.

Is every star a galaxy?

No, not all stars are in a galaxy. They may have once belonged to a galaxy, but they are not a part of it any more. Some of these so-called “stellar outcasts” or “intergalactic stars” have actually been observed by NASA’s Hubble Space Telescope.

Why is there no antimatter in space?

If antimatter and matter are truly identical but mirrored copies of each other, they should have been produced in equal amounts in the Big Bang. But today, there’s nearly no antimatter left in the universe – it appears only in some radioactive decays and in a small fraction of cosmic rays.

Is Andromeda made of antimatter?

No. There are too many galaxies in the Local Group for any one of them to be made of anti-matter and any of the others (such as ours) to be made of matter, without spectacular fireworks being seen at one place or another on a more or less continual basis.

Why do stars stay the same size for billions of years?

When it reaches 10 million degrees Celsius, nuclear fission begins. When the clump condenses it becomes a glowing star. The outward expanding force is balanced by the inward pull of gravity of the star. Hence the star stays in the same size and burns for billions of years.

What fraction of stars are found in multiple star systems?

The fraction of stars that are found in multiple star systems is actually a difficult measurement to make, but the fractions are likely higher than you might expect. For massive stars, we think a large fraction may be in multiple systems—for Sun-like stars it may be about half of all stars, and for low mass stars, less than half.

What causes the patterns of the Stars in the sky?

Although the stars move across the sky, they stay in the same patterns. This is because the apparent nightly motion of the stars is actually caused by the rotation of Earth on its axis. The patterns also shift in the sky with the seasons as Earth revolves around the Sun.

Where do stars have low temperature and high luminosity?

A number of stars, however, lie above the main sequence on the H–R diagram, in the upper-right region, where stars have low temperature and high luminosity. How can a star be at once cool, meaning each square meter on the star does not put out all that much energy, and yet very luminous?

https://www.youtube.com/watch?v=hOtqU64uLXs