There are many stars in the night sky, but there are not many of them that we can call names, and among them, in addition to the North Star, the Big Dipper is the most well-known star.
But if someone asks, what are the stars of the Big Dipper? How big are they? How far away is it from Earth? It is estimated that few people can answer clearly, but it does not matter, let's make up the knowledge about the Seven Stars of the Big Dipper.
The Big Dipper is located in the constellation Ursa Major, and we can find them in the night sky of the Northern Hemisphere almost every day under good observation conditions, and these seven shining stars form a unique spoon shape that is very easy to identify.
In the order from the first star at the top of the "spoon" to the tail of the "spoon", their names are: Dubhe, Merak, Phecda, Megrez, Alioth, Mizat, and Alkaid.
<h1 class="pgc-h-arrow-right" data-track="5" > celestial hub</h1>
Located about 123 light-years from Earth, the Hub is the farthest star from Earth among the Big Dipper stars, with a mass of about 4.25 times that of the Sun and 316 times the luminosity of the Sun.
Since the hub has now evolved to the giant stage, its surface temperature is only 4660 K, and its volume cannot be accurately determined, but it is certain that its radius is much larger than that of the Sun. In addition, the Pivot has a companion star with a mass of about 1.6 times that of the Sun, a distance of about 23 ASTRONOMICAL units and an orbital period of about 44.4 years.
<h1 class="pgc-h-arrow-right" data-track="5" > Tianxuan</h1>
The distance between Tianxuan and the Earth is about 79.4 light years, its radius is about 2.84 times that of the Sun, the mass is about 2.7 times that of the Sun, it is a sub-giant star that is about to enter the giant star stage, the "hydrogen fuel" of its core has been basically exhausted, and it is currently in the "hydrogen shell nuclear fusion" stage, its surface temperature is similar to that of the Sun, and its luminosity is 63 times that of the Sun.
<h1 class="pgc-h-arrow-right" data-track="5" ></h1>
It is about 83 light-years away from Earth, has a mass of about 2.94 times that of the Sun, a radius of about 3.04 times that of the Sun, and a surface temperature of 9355 K, which is 65 times the luminosity of the Sun. It is worth mentioning that past observations have shown that Tianji has a companion star with a mass of about 0.79 times that of the Sun, but in many recent observations, this companion star has not been observed.
<h1 class="pgc-h-arrow-right" data-track="5" > tianquan</h1>
Tianquan is the famous "Wenqu Star", which is also the faintest and least massive star in the Big Dipper. The distance between Tianquan and the Earth is about 80.5 light-years, the mass is about 1.63 times that of the Sun, the radius is about 1.4 times that of the Sun, the surface temperature is 8910 K, and the luminosity is only 14 times that of the Sun. It should also be said that Tianquan also has companion stars, and it is still two, but these two companion stars are too dim, and astronomers do not know much about them at present.
<h1 class="pgc-h-arrow-right" data-track="5" > Yuheng</h1>
Yuheng is about 82.6 light-years away from The Earth, with a radius of about 4.14 times that of the Sun, a mass of about 2.91 times that of the Sun, a surface temperature of 9020K, and a luminosity of 102 times that of the Sun. Although the luminosity of Yuheng is not as good as that of the Celestial Hub, because it is closer to the Earth, in the eyes of our earthlings, Yuheng is the brightest star in the Seven Stars of the Big Dipper. Astronomers have long suspected that Yuheng also has a companion star, but has not yet been found.
<h1 class="pgc-h-arrow-right" data-track="5" > Kaiyang</h1>
The distance between Kaiyang and the Earth is about 82.9 light years, the mass is about 2.2 times that of the Sun, the radius is about 2.4 times that of the Sun, the surface temperature is 9000 K, and the luminosity is 33 times that of the Sun. If the observation conditions are good, we can tell with the naked eye that there is a faint star near Kaiyang, and in fact, there are 4 stars in this area, which together form a hexagram system.
<h1 class="pgc-h-arrow-right" data-track="5" > Yaoguang</h1>
Among the Seven Stars of the Big Dipper, except for Tianshu and Tianxuan, the other stars are in the main sequence star stage, and Yaoguang is the most "young" because its age is only about 10 million years. In addition, Yaoguang also has three "Big Dippers", namely the most massive (6.1 times the mass of the Sun), the highest surface temperature (15540K), and the strongest luminosity (594 times the luminosity of the Sun).
However, since the radius of Yaoguang is only 3.4 times that of the Sun, and its distance from the Earth is relatively far (about 104 light years), it can only be regarded as the third brightest star in our eyes (the first and second are Yuheng and Tianshu, respectively).
By the way, the Big Dipper is not static, with the movement of the earth, their relative position in the night sky will also change regularly, it looks like the Big Dipper seven stars this "spoon" rotates in the sky, interestingly, when the "spoon handle" points to the southeast and northwest, the corresponding season on the earth is just spring, summer, autumn and winter.
Well, today we will talk about this first, welcome to pay attention to us, we will see you next time.
(Some of the pictures in this article are from the Internet, if there is infringement, please contact the author to delete)