What is a star?

Question 1: What does the star mean? Stars are spherical or quasi-spherical objects made of hot gas, which can emit light by themselves. Stars are gas planets. The brightness of a star is usually expressed in magnitude.

The sun is a star because it shines. The moon is not, because it reflects sunlight. The moon is only a satellite of the earth, and the stars are stars.

Thirdly, the definition of "planet" is 1, which must be a celestial body orbiting a star;

2. The mass must be large enough, and its own gravity must be balanced with the rotational speed to make it spherical;

There can't be a celestial body bigger than it in orbit.

At present, there are eight planets in the solar system, namely: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Question 2: Which stars are Betelgeuse? Betelgeuse is a red Supergiant star in Orion? It is the twelfth brightest star in the night sky except the sun. In the winter night sky, it forms a winter triangle with Sirius in Canis major and Nanhe III in Canis minor. Although it is the alpha star of Orion, the actual beta star of Orion (Betelgeuse) is brighter than it. Constellation: Orion star position: 05h 55m 10.3053s, declination+07 24' 25.426 ÷ visual magnitude (v): 0.58, etc. (0.3 1.2) Betelgeuse (upper left) Spectral classification: M2Iab (red Supergiant star). B-V color index 1.85 (orange red), U-B color index 2.06 Variable star type: SR c (semi-regular variable star), radial velocity (RV):+2 1.0 km/s, self-propelled (μ) Ra: 24.95 0.08 mas. 58 Ori，HR 206 1，BD+7 1055，HD 3980 1，SAO 1 1327 1，FK5 224，HIP 27989。

Antares

Antares, the alpha star of Scorpio (the main star of Scorpio), also known as fire in ancient China, belongs to the seven-night antares of the Eastern Black Dragon (Antares has three stars, namely Scorpio σ, α, τ, also known as Antares I, Antares II and Antares III). ), used to determine the season. "Fire in July" means that Mars is heading west and the weather is cold. Antares is the15th bright star in the whole day, which is a visual binary star. The magnitude of the main star is 1.2, and the red giant with M 1I is 6000 times the brightness of the sun. The companion star is a blue dwarf star with brightness of 5.4 and angular distance of 3 ". The synthetic magnitude is 0.96 and the absolute magnitude is -4.7. 600 light years away. Modern astronomy is called "Scorpius alpha star [1]". This is a red Supergiant star. It is a semi-regular variable star with obvious light variation and forms a visual binary system with a blue main sequence star. Antares or radio sources. The main star of Antares is actually a semi-regular variable star, with a brightness of 0.9 to 1.8 and a dimming period of 48 years. The surface temperature is 3600K, the radius is 700 times that of the sun, the surface area is 360000 times that of the sun, and the mass is 15.5 times that of the sun. AntAres, the English name of AntAres, is a combination of Anti and ares. Ares is the name of God of War and Mars in Greek mythology, which means "the enemy of Mars". Because the brightness and color of Antares are very similar to those of Mars, and the orbits of both stars are on the ecliptic, when Mars runs to Scorpio, two red stars shine in the sky, so Antares is named. In ancient Persia, Antares, Bi Suwu, Xuanyuan XIV and Beiluoshimen were collectively called the four heavenly kings.

Question 3: What are the characteristics of a star? Stars are composed of hot gases. They are spherical or quasi-spherical objects that can emit light by themselves. The stars overhead are all gas planets. Without special tools and methods, it is difficult to find their position changes in the sky.

Question 4: Definition of a star A star is composed of hot gas. It is a spherical or quasi-spherical celestial body that can emit light by itself. Because the stars are too far away from us, it is difficult to find their position changes in the sky without special tools and methods, so the ancients regarded them as fixed stars. The sun, the main star of our solar system, is a star.

Question 5: What is a star? A star refers to a star in the universe that can generate heat through the energy generated by nuclear fusion and emit light by itself. In the past, astronomers thought that the position of constant stars was eternal, hence the name. But in fact. Stars will also follow a certain trajectory and rotate around the center of their galaxies. Stars are the most basic members of the universe.

Question 6: What is a star and what is a planet? Their concept of a star refers to a star in the universe that can generate heat and glow by itself with the energy generated by nuclear fusion. In the past, astronomers thought that the position of constant stars was eternal, hence the name. But in fact. Stars will also follow a certain trajectory around the center of their galaxies. Stars are the most basic members of the universe.

Planets are celestial bodies that do not emit light by themselves and surround stars. Generally speaking, a planet needs to have a certain mass, and the mass of the planet should be large enough to make its shape about spherical. Those with insufficient mass are called asteroids. The names of the planets come from the fact that their positions in the sky are not fixed, just as they are walking. Mercury, Venus, Mars, Jupiter and Saturn, the five planets visible to the naked eye in the solar system, were discovered by humans as early as prehistoric times. Later, humans learned that the earth itself is also a planet.