Most people today live in cities, and due to light pollution and smog, few stars in the night sky can be seen. In fact, in places with less light pollution, looking at the night sky on a clear night, if the air transparency is high, you can see the stars in the sky. So among so many stars, which ones are closer to us? What are you far from us?
The closest natural celestial body to us is the moon, with an average of only 380,000 kilometers. It is not large, only 3,476 kilometers in diameter, less than 1/3 of the earth, but because it is the closest, the moon looks like the sun. The viewing area is almost the same size.
The average distance between the eight planets is Venus. The most recent time is only about 40 million kilometers, which can reflect the sun very well, so it is also the brightest star in the night sky except the moon.
Among the eight planets, we can see Mercury, Venus, Mars, Jupiter, Saturn, and Uranus. The farthest Uranus (average distance of 2.88 billion kilometers from the Sun) is only 5.38, barely visible, but because it is too Inconspicuous, the ancients never used it as a planet. The farthest Neptune (about 4.5 billion kilometers from the Sun) is invisible.
The star closest to us is the sun, about 149 million kilometers. The star closest to the solar system outside the sun is the neighboring star. It is only 4.22 light years. It is a red dwarf star with a mass of only 12% of the sun and its volume is not large. The surface temperature is less than 3000 degrees Celsius, so the emitted light is very weak, and the apparent magnitude is about 12, etc. It can’t be seen without a telescope, so the star closest to our solar system cannot be seen.
Among the stars we are familiar with, Haishan 2 is quite far away from us. It is about 7500 light years, and its apparent magnitude is 4.3. This is a massive star with a mass more than 100 times that of the sun. The crystal activity is more intense, so it can It emits extremely bright light. In 1843, it suddenly became brighter. Its brightness was second only to Sirius in the stars, reaching -0.8, etc. It was brighter than the old star and the South Gate II, which is only 4.37 light years away from the solar system. It is related to one of its outbreaks. However, due to the distance, it is still bleak for most of the time.
However, Haishan II is not the farthest star we can see. From the data point of view, HIP54751, which is 12,000 light-years away from us, is the most distant star that can be visually observed. Its apparent magnitude is 4.55, but in fact its The luminosity is 185,000 times that of the sun, and its absolute star can reach -8.35. If it is placed far away from our 32 light years (absolute star equidistance), it will be as bright as the moon we see. The reason why this star is so bright is because it is a star with a dramatic change in the star’s main sequence at the end of the star. Its mass is about 30 times that of the sun, but its volume is very large, and the temperature of the star is very high. The light is very strong.
But the farthest object that human eyes can see is not a star, but some galaxies outside the Milky Way. For example, the Andromeda galaxy is about 2.56 million light years away from us, but the most distant celestial body is the triangular galaxies. About 2.92 million light years, depending on the magnitude of 5.73, etc., very sunny night, barely visible in the sky northwest of the northern hemisphere, but this is similar to our Milky Way, a huge galaxy with hundreds of billions of stars, looks It’s just a faint star point.