How far apart are the stars that make up the constellation?

In places where there is not much light pollution in the northern hemisphere, as long as the weather is clear at night, you can see the romantic astronomical landscape-the summer triangle without any astronomical observation equipment.

The reason why this astronomical landscape is named "Romance" is that this combination contains a romantic love story. If you are not an astronomy enthusiast, you may not be familiar with the term "Summer Triangle", but you must have heard the story of the Cowherd and the Weaver Girl. As one of the three ancient folk tales in China, no one in China would know, and the combination of "Summer Triangle" is actually the combination of Cowherd and Weaver Girl. The three stars that make up the summer triangle are Vega, Hegu and Tianjin. With Vega, where is Altair? Altair is actually a river drum star. The reason why it is not directly called Altair is because the so-called Hegu Star is actually a multi-star combination.

The river drum star in the summer triangle consists of three stars, one of which is the brightest star, namely the river drum II, which is what we call the Altair, while the stars on both sides of the River drum II are low in brightness, symbolizing the legendary two children of the Cowherd and the Weaver Girl. The whole three-star combination symbolizes that the Cowherd is carrying a pole with two children of him and the Weaver Girl at both ends.

With Weaver Girl and Cowherd, what about Tianjin Star in the Summer Triangle? First of all, Tianjin Star has nothing to do with Tianjin. Tianjin Star, like Hegu Star, is a multi-star combination. The difference is that Tianjin Star is composed of four stars, and the brightest one is Tianjin IV, which is the one we can see when we look up in the summer triangle. Tianjin Star Bridge is a legendary bridge connecting cowherd and weaver girl. It is because of this legend that the summer triangle is considered to be the most romantic.

People habitually think that the stars in these combinations may be very close to each other, but in fact they are not.

Because the universe itself is very empty and the distance between stars is very far, it should be calculated in light years. In the summer triangle, Altair is closest to the solar system, about 16.7 light years away, followed by Vega, about 25 light years away. From the numerical point of view, the difference between the two does not seem to be too much, but for humans, it is in light years.

If the distance between the cowherd and the weaver girl is acceptable, then Tianjin Star, the third member of the Summer Triangle, can be said to be far away. The distance from Tianjin Star to the solar system is uncertain, but it is certain that it is at least 1000 light-years away from the solar system. At present, the most conservative estimate is 1340 light years, and the boldest estimate is 2600 light years.

1000 light-year, from the human point of view, is an unimaginable distance. Even if flying at the speed of light, it will take more than 1000 years to arrive. This distance is enough for human beings to feel their own smallness just by thinking about it.

So how can we directly see the stars beyond 1000 light years? You can see it clearly. The reason is that Tianjin IV has great mass, volume and brightness. The mass of Tianjin IV is more than 20 times that of the sun, but its volume is more than 8 million times that of the sun and its brightness is about 80,000 times that of the sun. Because of this, the absolute magnitude of Tianjin IV reached -8.37, and the apparent magnitude was around 1.2. Looking at the whole night sky, Tianjin IV can be regarded as the first 19 bright star in the whole day. The huge mass and volume allow Tianjin IV, a star 65,438+0,000 light years away, to be directly observed by us. So, are there any bigger and farther stars in the universe that we can directly observe with the naked eye?

The universe is vast and ubiquitous. Although Tianjin IV is huge and far away, it is not the farthest star visible to the naked eye in the night sky. The farthest star you can see in the night sky is HIP5475 1.

We feel that Tianjin IV is 1000 light years away from us, but compared with HIP5475 1, Tianjin IV is really close, because the distance between HIP5475 1 and the solar system has reached more than 12000 light years, that is to say, it will only take 12000 years. So the light we see at the bottom of the ship HIP5475 1 is actually the light before 12000. It is so far away from us, why can we still see it with the naked eye? Because it is bigger, much bigger than Tianjin IV, and its volume can reach tens of millions of times that of the sun. Although HIP5475 1 is so huge, it is too far away from us, so although it is visible to the naked eye, its brightness is very weak.