What kind of star is a planet?

After thousands of years of exploration, it was not until Copernicus established the heliocentric theory in the 16th century that it was generally recognized that the earth is one of the planets revolving around the sun, and the nine planets, including the earth, constitute a planetary system revolving around the sun - the main members of the solar system. Planets themselves generally do not emit light, but shine by reflecting sunlight from their surfaces.

On a background of a sky composed mostly of stars, there is a noticeable relative movement of the planets. The closest planet to the Sun is Mercury, followed by Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Starting from the fact that the planets originate from different forms of matter, the nine planets can be divided into three categories:

Earth-like planets (including water, metal, earth, fire), giant planets (wood, earth) and perihelia planets (kings, sea kings, pluto). The motion of the planets around the sun is called revolution, and the orbit of the planets has three characteristics: coplanarity, isotropy, and near-circularity. The so-called coplanarity refers to the fact that the orbital planes of the nine planets are almost in the same plane; Isotropy, which means that they revolve around the Sun in the same direction; Whereas, near-circularity means that their orbits are quite close to the circle.

Around some planets, there are rings of matter orbiting the planets, which are made up of a large number of small objects (such as rocks, ice blocks, etc.), which glow due to the reflection of sunlight, called planetary rings. Before the 70s of the 20th century, people always thought that only Saturn had rings, and later discovered that Uranus and Jupiter also had rings, which provided new information for the study of the origin and evolution of the solar system.

Planets were originally defined as opposed to stars, and at the same time of year, the position of the star in the sky is relatively fixed, like a fixed gem set in the celestial sphere. However, the position of the planets in the sky is constantly changing, as if walking on the celestial sphere, so they are called planets. A modern planet is a star that orbits a star that does not emit light and heats up in itself.

What doesn't shine is a planet. It has its own orbit, mass, and usually orbits around a large celestial body's star.

1.Does not emit light.

2.There is a certain quality.

3.There is a certain size.

4.Globosity. 5.Dominates in the surrounding cosmic position.

Stars that revolve around a star do not emit light or heat on their own.

It has its own running track, and it has a certain attraction in itself.

And there is a certain quality.

If you follow the definitions of the above points, then the Moon is also a planet.

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

One of the eight planets, in ancient China it was called Taibai or Taibai Shielding Traveling Star. It is sometimes the morning star, which appears in the eastern sky before dawn and teases, and is called "enlightenment"; Sometimes it is a twilight star, which appears in the western sky after dusk, and is called the spring stool "Chang Gung".

Venus is the brightest star in the whole day after the sun and moon, like a dazzling diamond, so the ancient Greeks called it Aphrodite - the goddess of love and beauty, and the Romans called it Venus - the goddess of beauty.

How long are planets alive:

Stars have an infinitely long lifespan, and in the absence of special circumstances, such as collisions with other planets, etc., then planets can have the same lifespan as the universe, and as long as the universe is still there, then the planets still exist. We all know that planets orbit stars, and stars have lifespans, and their lifespans are between 10 and 10 billion years old.

As a result, stars are dying, becoming white dwarfs, neutron stars, or black holes. Since planets orbit stars, and stars die, what happens to the planets that orbit around them after the star dies? In fact, even if a star dies, the planets orbiting it will not be threatened with death.

When a star dies and becomes another celestial body, the planet adjusts its orbit and orbits around the star's remnants.

Planets: Usually refers to the eight planets from small to large according to their distance from the Sun, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Most of the stars are stars, and only Venus, Jupiter, Mars, Saturn, and Mercury are planets that can be seen with the naked eye.

If you are looking at the stars at night and want to distinguish which planets are, the simplest and most obvious difference is:

1. Planets are usually much brighter than other stars (stars).

2. The planetary light is stable and will not flicker. Whereas the light of other stars is twinkling and blinking.

When observed, bright and twinkling stars are stars, and because the planets themselves do not emit light, they shine by reflecting the sun's light, so their brightness is relatively weak. Whereas stars emit light on their own, spheroids made up of hot gas. Therefore, the stars seen in the sky at night are mostly stars, and the stars are visible with the naked eye.

A galaxy is a system of countless galaxies and dust. Generally, it is divided into three categories: elliptical galaxies, spiral galaxies, and irregular galaxies. In general, planets and stars are galaxies.

Planets are celestial bodies that orbit stars, and there are nine planets that we now know as Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Among the planets that can be seen with the naked eye are: Mercury, Venus, Earth, Mars, Jupiter, Saturn.

The Sun is a star.

From the ground, all stars (except the Moon) are point lights, but there is a difference between planets and stars.

In general, planets are noticeably brighter than stars. And because the planet is closer to Earth, it doesn't look like a star, and its luminosity doesn't change. Stars are so far away that their light in the atmosphere is affected by the flow of air and is twinkling.

That is to say, the ones that are brighter and do not twinkle are the planets. Twinkling stars are stars.

Galaxies and nebulae are more difficult to distinguish. It wasn't until the 19th century that astronomers could tell the difference between galaxies and nebulae because they looked like blurred spots. So much so that some galaxies are still called nebulae, such as the Andromeda Nebula and the Large and Small Magellanic Nebulae, which are actually extragalactic galaxies.

Moreover, neither the Messier catalog (number M) nor the new general table (number NGC), which number galaxies and nebulae, distinguish between galaxies and nebulae.

In general, in telescopes, galaxies are elliptical, while nebulae vary in shape, from diffuse (diffuse nebula) to round or oval (planetary nebula). In addition, galaxies generally have regular and obvious edges, and nebula edges are not obvious.

A star satellite orbiting a planet, and a star orbiting a star is called a planet. For example, the Sun is the star, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune are its planets, and the Moon is the Earth's moon. Do you understand?

Fixed star. Planet.

It usually refers to a celestial body that does not emit light of its own light and orbits a star. Its rotation is often in the same direction as the rotation of the star it orbits. Generally speaking, planets need to have a certain mass, and the mass of the planet must be large enough to be nearly spherical, and it cannot undergo nuclear fusion reactions like stars.

A star is a spherical luminous plasma held together by gravity, and the Sun is the closest star to Earth. Almost all of the other stars that can be seen on Earth at night are within the Milky Way, but due to their distance, these stars appear to be just fixed points of light. Historically, the more prominent stars have been grouped into constellations and constellations, with the brightest stars having their own traditional names.

Astronomers have assembled a catalog of stars that provides criteria for the naming of many different stars.

Stars that orbit planets periodically in regular orbits are called "moons".